diff --git a/nixos/doc/manual/default.nix b/nixos/doc/manual/default.nix
index a79a77f40df1..e118f8b89437 100644
--- a/nixos/doc/manual/default.nix
+++ b/nixos/doc/manual/default.nix
@@ -67,7 +67,7 @@ in rec {
 
       # Generate the HTML manual.
       dst=$out/share/doc/nixos
-      ensureDir $dst
+      mkdir -p $dst
       xsltproc $xsltFlags --nonet --xinclude \
         --output $dst/manual.html \
         ${pkgs.docbook5_xsl}/xml/xsl/docbook/xhtml/docbook.xsl \
diff --git a/nixos/lib/make-iso9660-image.sh b/nixos/lib/make-iso9660-image.sh
index 89b681ed2cd5..675b5bb35148 100644
--- a/nixos/lib/make-iso9660-image.sh
+++ b/nixos/lib/make-iso9660-image.sh
@@ -78,7 +78,7 @@ done
 cat pathlist | sed -e 's/=\(.*\)=\(.*\)=/\\=\1=\2\\=/' | tee pathlist.safer
 
 
-ensureDir $out/iso
+mkdir -p $out/iso
 genCommand="genisoimage -iso-level 4 -r -J $bootFlags -hide-rr-moved -graft-points -path-list pathlist.safer ${volumeID:+-V $volumeID}"
 if test -z "$compressImage"; then
     $genCommand -o $out/iso/$isoName
@@ -87,5 +87,5 @@ else
 fi
 
 
-ensureDir $out/nix-support
+mkdir -p $out/nix-support
 echo $system > $out/nix-support/system
diff --git a/nixos/lib/make-system-tarball.sh b/nixos/lib/make-system-tarball.sh
index aadd0f6428c8..096d96ac1c81 100644
--- a/nixos/lib/make-system-tarball.sh
+++ b/nixos/lib/make-system-tarball.sh
@@ -48,11 +48,11 @@ for ((n = 0; n < ${#objects[*]}; n++)); do
     fi
 done
 
-ensureDir $out/tarball
+mkdir -p $out/tarball
 
 tar cvJf $out/tarball/$fileName.tar.xz *
 
-ensureDir $out/nix-support
+mkdir -p $out/nix-support
 echo $system > $out/nix-support/system
 echo "file system-tarball $out/tarball/$fileName.tar.xz" > $out/nix-support/hydra-build-products
 
diff --git a/nixos/modules/services/amqp/activemq/default.nix b/nixos/modules/services/amqp/activemq/default.nix
index f1f3d005f30f..1862e17de0b5 100644
--- a/nixos/modules/services/amqp/activemq/default.nix
+++ b/nixos/modules/services/amqp/activemq/default.nix
@@ -12,7 +12,7 @@ let
     phases = [ "installPhase" ];
     buildInputs = [ jdk ];
     installPhase = ''
-      ensureDir $out/lib
+      mkdir -p $out/lib
       source ${activemq}/lib/classpath.env
       export CLASSPATH
       ln -s "${./ActiveMQBroker.java}" ActiveMQBroker.java
diff --git a/nixos/modules/services/hardware/acpid.nix b/nixos/modules/services/hardware/acpid.nix
index a710636c1400..03daab0d4882 100644
--- a/nixos/modules/services/hardware/acpid.nix
+++ b/nixos/modules/services/hardware/acpid.nix
@@ -6,7 +6,7 @@ let
 
   acpiConfDir = pkgs.runCommand "acpi-events" {}
     ''
-      ensureDir $out
+      mkdir -p $out
       ${
         # Generate a configuration file for each event. (You can't have
         # multiple events in one config file...)
diff --git a/nixos/modules/services/monitoring/nagios.nix b/nixos/modules/services/monitoring/nagios.nix
index 97d153153a55..c1f7ba0eca74 100644
--- a/nixos/modules/services/monitoring/nagios.nix
+++ b/nixos/modules/services/monitoring/nagios.nix
@@ -12,7 +12,7 @@ let
   nagiosObjectDefs = cfg.objectDefs;
 
   nagiosObjectDefsDir = pkgs.runCommand "nagios-objects" {inherit nagiosObjectDefs;}
-    "ensureDir $out; ln -s $nagiosObjectDefs $out/";
+    "mkdir -p $out; ln -s $nagiosObjectDefs $out/";
 
   nagiosCfgFile = pkgs.writeText "nagios.cfg"
     ''
diff --git a/nixos/modules/services/monitoring/systemhealth.nix b/nixos/modules/services/monitoring/systemhealth.nix
index b0e59595e133..20d1dadd3bf2 100644
--- a/nixos/modules/services/monitoring/systemhealth.nix
+++ b/nixos/modules/services/monitoring/systemhealth.nix
@@ -13,7 +13,7 @@ let
     };
     buildInputs = [ python ];
     installPhase = ''
-      ensureDir $out/bin
+      mkdir -p $out/bin
       # Make it work for kernels 3.x, not so different than 2.6
       sed -i 's/2\.6/4.0/' system_health.py
       cp system_health.py $out/bin
diff --git a/nixos/modules/services/network-filesystems/openafs-client/default.nix b/nixos/modules/services/network-filesystems/openafs-client/default.nix
index b34ebc3663e3..5c539ba306ae 100644
--- a/nixos/modules/services/network-filesystems/openafs-client/default.nix
+++ b/nixos/modules/services/network-filesystems/openafs-client/default.nix
@@ -11,7 +11,7 @@ let
   };
 
   afsConfig = pkgs.runCommand "afsconfig" {} ''
-    ensureDir $out
+    mkdir -p $out
     echo ${cfg.cellName} > $out/ThisCell
     cp ${cellServDB} $out/CellServDB
     echo "/afs:${cfg.cacheDirectory}:${cfg.cacheSize}" > $out/cacheinfo
diff --git a/nixos/modules/services/networking/ircd-hybrid/builder.sh b/nixos/modules/services/networking/ircd-hybrid/builder.sh
index b8cb836db95e..f2c92878a4dc 100644
--- a/nixos/modules/services/networking/ircd-hybrid/builder.sh
+++ b/nixos/modules/services/networking/ircd-hybrid/builder.sh
@@ -3,7 +3,7 @@ source $stdenv/setup
 doSub() {
     local src=$1
     local dst=$2
-    ensureDir $(dirname $dst)
+    mkdir -p $(dirname $dst)
     substituteAll $src $dst
 }
 
@@ -28,4 +28,4 @@ for i in $substFiles; do
     fi
 done
 
-ensureDir $out/bin
+mkdir -p $out/bin
diff --git a/nixos/modules/services/system/dbus.nix b/nixos/modules/services/system/dbus.nix
index 8d02a6404ac1..928f16c94489 100644
--- a/nixos/modules/services/system/dbus.nix
+++ b/nixos/modules/services/system/dbus.nix
@@ -14,7 +14,7 @@ let
     name = "dbus-conf";
     preferLocalBuild = true;
     buildCommand = ''
-      ensureDir $out
+      mkdir -p $out
 
       cp -v ${pkgs.dbus.daemon}/etc/dbus-1/system.conf $out/system.conf
 
diff --git a/nixos/modules/services/web-servers/apache-httpd/default.nix b/nixos/modules/services/web-servers/apache-httpd/default.nix
index b8359d4756b3..a6f856912533 100644
--- a/nixos/modules/services/web-servers/apache-httpd/default.nix
+++ b/nixos/modules/services/web-servers/apache-httpd/default.nix
@@ -80,7 +80,7 @@ let
 
   # !!! should be in lib
   writeTextInDir = name: text:
-    pkgs.runCommand name {inherit text;} "ensureDir $out; echo -n \"$text\" > $out/$name";
+    pkgs.runCommand name {inherit text;} "mkdir -p $out; echo -n \"$text\" > $out/$name";
 
 
   enableSSL = any (vhost: vhost.enableSSL) allHosts;
@@ -194,7 +194,7 @@ let
     ) null ([ cfg ] ++ subservices);
 
     documentRoot = if maybeDocumentRoot != null then maybeDocumentRoot else
-      pkgs.runCommand "empty" {} "ensureDir $out";
+      pkgs.runCommand "empty" {} "mkdir -p $out";
 
     documentRootConf = ''
       DocumentRoot "${documentRoot}"
diff --git a/nixos/modules/services/web-servers/apache-httpd/mediawiki.nix b/nixos/modules/services/web-servers/apache-httpd/mediawiki.nix
index 7d59c13b9575..0693ca57814a 100644
--- a/nixos/modules/services/web-servers/apache-httpd/mediawiki.nix
+++ b/nixos/modules/services/web-servers/apache-httpd/mediawiki.nix
@@ -90,7 +90,7 @@ let
 
     installPhase =
       ''
-        ensureDir $out
+        mkdir -p $out
         cp -r * $out
         cp ${mediawikiConfig} $out/LocalSettings.php
         sed -i 's|/bin/bash|${pkgs.stdenv.shell}|' \
@@ -103,7 +103,7 @@ let
   mediawikiScripts = pkgs.runCommand "mediawiki-${config.id}-scripts"
     { buildInputs = [ pkgs.makeWrapper ]; }
     ''
-      ensureDir $out/bin
+      mkdir -p $out/bin
       for i in changePassword.php createAndPromote.php userOptions.php edit.php nukePage.php update.php; do
         makeWrapper ${php}/bin/php $out/bin/mediawiki-${config.id}-$(basename $i .php) \
           --add-flags ${mediawikiRoot}/maintenance/$i
diff --git a/nixos/modules/services/web-servers/apache-httpd/mercurial.nix b/nixos/modules/services/web-servers/apache-httpd/mercurial.nix
index 755b595c783d..82da3330b00a 100644
--- a/nixos/modules/services/web-servers/apache-httpd/mercurial.nix
+++ b/nixos/modules/services/web-servers/apache-httpd/mercurial.nix
@@ -9,7 +9,7 @@ let
   cgi = pkgs.stdenv.mkDerivation {
     name = "mercurial-cgi";
     buildCommand = ''
-      ensureDir $out
+      mkdir -p $out
       cp -v ${mercurial}/share/cgi-bin/hgweb.cgi $out
       sed -i "s|/path/to/repo/or/config|$out/hgweb.config|" $out/hgweb.cgi
       echo "
diff --git a/nixos/modules/services/x11/display-managers/lightdm.nix b/nixos/modules/services/x11/display-managers/lightdm.nix
index d459c59b0483..f8ce06738fee 100644
--- a/nixos/modules/services/x11/display-managers/lightdm.nix
+++ b/nixos/modules/services/x11/display-managers/lightdm.nix
@@ -26,7 +26,7 @@ let
     buildInputs = [ pkgs.makeWrapper ];
 
     buildCommand = ''
-      ensureDir $out/gtk-3.0/
+      mkdir -p $out/gtk-3.0/
 
       # This wrapper ensures that we actually get fonts
       makeWrapper ${pkgs.lightdm_gtk_greeter}/sbin/lightdm-gtk-greeter \
diff --git a/nixos/modules/services/x11/display-managers/slim.nix b/nixos/modules/services/x11/display-managers/slim.nix
index 48feb12d044c..9ee4e0dc7cb0 100644
--- a/nixos/modules/services/x11/display-managers/slim.nix
+++ b/nixos/modules/services/x11/display-managers/slim.nix
@@ -27,7 +27,7 @@ let
       unpackedTheme = pkgs.stdenv.mkDerivation {
         name = "slim-theme";
         buildCommand = ''
-          ensureDir $out
+          mkdir -p $out
           cd $out
           unpackFile ${cfg.theme}
           ln -s * default
diff --git a/nixos/modules/system/boot/stage-1.nix b/nixos/modules/system/boot/stage-1.nix
index b6249b6c0915..f894f5bfbc1b 100644
--- a/nixos/modules/system/boot/stage-1.nix
+++ b/nixos/modules/system/boot/stage-1.nix
@@ -140,7 +140,7 @@ let
   udevRules = pkgs.stdenv.mkDerivation {
     name = "udev-rules";
     buildCommand = ''
-      ensureDir $out
+      mkdir -p $out
 
       echo 'ENV{LD_LIBRARY_PATH}="${extraUtils}/lib"' > $out/00-env.rules
 
diff --git a/nixos/modules/tasks/tty-backgrounds-combine.sh b/nixos/modules/tasks/tty-backgrounds-combine.sh
index 1e0d8758a6ee..55c3a1ebfa8a 100644
--- a/nixos/modules/tasks/tty-backgrounds-combine.sh
+++ b/nixos/modules/tasks/tty-backgrounds-combine.sh
@@ -3,7 +3,7 @@ source $stdenv/setup
 ttys=($ttys)
 themes=($themes)
 
-ensureDir $out
+mkdir -p $out
 
 defaultName=$(cd $default && ls | grep -v default)
 echo $defaultName
diff --git a/nixos/modules/virtualisation/qemu-vm.nix b/nixos/modules/virtualisation/qemu-vm.nix
index bccf6583e47d..16c3836887cc 100644
--- a/nixos/modules/virtualisation/qemu-vm.nix
+++ b/nixos/modules/virtualisation/qemu-vm.nix
@@ -379,7 +379,7 @@ in
 
     system.build.vm = pkgs.runCommand "nixos-vm" { preferLocalBuild = true; }
       ''
-        ensureDir $out/bin
+        mkdir -p $out/bin
         ln -s ${config.system.build.toplevel} $out/system
         ln -s ${pkgs.writeScript "run-nixos-vm" startVM} $out/bin/run-${vmName}-vm
       '';
diff --git a/pkgs/applications/audio/espeak/edit.nix b/pkgs/applications/audio/espeak/edit.nix
index eb34335721f0..6627c6eb0e52 100644
--- a/pkgs/applications/audio/espeak/edit.nix
+++ b/pkgs/applications/audio/espeak/edit.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp espeakedit $out/bin
   '';
 
diff --git a/pkgs/applications/audio/mixxx/default.nix b/pkgs/applications/audio/mixxx/default.nix
index b76eecc9e4ad..e3422d4ba069 100644
--- a/pkgs/applications/audio/mixxx/default.nix
+++ b/pkgs/applications/audio/mixxx/default.nix
@@ -28,7 +28,7 @@ stdenv.mkDerivation rec {
 
   buildPhase = ''
     runHook preBuild
-    ensureDir "$out"
+    mkdir -p "$out"
     scons \
       -j$NIX_BUILD_CORES -l$NIX_BUILD_CORES \
       $sconsFlags "prefix=$out"
diff --git a/pkgs/applications/audio/praat/default.nix b/pkgs/applications/audio/praat/default.nix
index b8a283125fc4..c7a40bf85a7c 100644
--- a/pkgs/applications/audio/praat/default.nix
+++ b/pkgs/applications/audio/praat/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp praat $out/bin
   '';
 
diff --git a/pkgs/applications/editors/atom/default.nix b/pkgs/applications/editors/atom/default.nix
index 725b4520e699..51844f641794 100644
--- a/pkgs/applications/editors/atom/default.nix
+++ b/pkgs/applications/editors/atom/default.nix
@@ -43,8 +43,8 @@ in stdenv.mkDerivation rec {
   phases = [ "installPhase" ];
 
   installPhase = ''
-    ensureDir $out/share/atom
-    ensureDir $out/bin
+    mkdir -p $out/share/atom
+    mkdir -p $out/bin
     tar -C $out/share/atom -xvf $src
     patchelf --set-interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" \
       $out/share/atom/atom
diff --git a/pkgs/applications/editors/dhex/default.nix b/pkgs/applications/editors/dhex/default.nix
index 45b7de900e26..7a0e9e59d7e5 100644
--- a/pkgs/applications/editors/dhex/default.nix
+++ b/pkgs/applications/editors/dhex/default.nix
@@ -12,9 +12,9 @@ stdenv.mkDerivation rec {
   buildInputs = [ ncurses ];
  
   installPhase = ''
-    ensureDir $out/bin
-    ensureDir $out/share/man/man1
-    ensureDir $out/share/man/man5
+    mkdir -p $out/bin
+    mkdir -p $out/share/man/man1
+    mkdir -p $out/share/man/man5
 
     cp dhex $out/bin
     cp dhex.1 $out/share/man/man1
diff --git a/pkgs/applications/editors/emacs-modes/calfw/default.nix b/pkgs/applications/editors/emacs-modes/calfw/default.nix
index 8934238ffa3a..3015865e3bf8 100644
--- a/pkgs/applications/editors/emacs-modes/calfw/default.nix
+++ b/pkgs/applications/editors/emacs-modes/calfw/default.nix
@@ -16,10 +16,10 @@ stdenv.mkDerivation rec {
 
   installPhase =
     ''
-       ensureDir "$out/share/doc/${name}"
+       mkdir -p "$out/share/doc/${name}"
        cp -v readme.md "$out/share/doc/${name}"
 
-       ensureDir "$out/share/emacs/site-lisp/"
+       mkdir -p "$out/share/emacs/site-lisp/"
        cp *.el "$out/share/emacs/site-lisp/"
     '';
 
diff --git a/pkgs/applications/editors/emacs-modes/ocaml/default.nix b/pkgs/applications/editors/emacs-modes/ocaml/default.nix
index 1d81a0b7ff1e..9e4496ff1a48 100644
--- a/pkgs/applications/editors/emacs-modes/ocaml/default.nix
+++ b/pkgs/applications/editors/emacs-modes/ocaml/default.nix
@@ -18,7 +18,7 @@ in stdenv.mkDerivation {
 
   installPhase = ''
     cd emacs;
-    ensureDir "$out/share/emacs/site-lisp" "$out/bin"
+    mkdir -p "$out/share/emacs/site-lisp" "$out/bin"
     EMACSDIR=$out/share/emacs/site-lisp make simple-install install-ocamltags
   '';
 
diff --git a/pkgs/applications/editors/emacs-modes/tuareg/default.nix b/pkgs/applications/editors/emacs-modes/tuareg/default.nix
index 17957ffc276b..3fd592f3dba6 100644
--- a/pkgs/applications/editors/emacs-modes/tuareg/default.nix
+++ b/pkgs/applications/editors/emacs-modes/tuareg/default.nix
@@ -15,7 +15,7 @@ in stdenv.mkDerivation {
   buildInputs = [ emacs ];
 
   installPhase = ''
-    ensureDir "$out/share/emacs/site-lisp"
+    mkdir -p "$out/share/emacs/site-lisp"
     cp *.el *.elc  "$out/share/emacs/site-lisp"
   '';
 
diff --git a/pkgs/applications/editors/vim/macvim.nix b/pkgs/applications/editors/vim/macvim.nix
index e48cb2590f9c..8b8f08b6fd73 100644
--- a/pkgs/applications/editors/vim/macvim.nix
+++ b/pkgs/applications/editors/vim/macvim.nix
@@ -62,7 +62,7 @@ in mkDerivation rec {
   '';
 
   postInstall = ''
-    ensureDir $out/Applications
+    mkdir -p $out/Applications
     cp -r src/MacVim/build/Release/MacVim.app $out/Applications
 
     rm $out/bin/{Vimdiff,Vimtutor,Vim,ex,rVim,rview,view}
diff --git a/pkgs/applications/graphics/alchemy/default.nix b/pkgs/applications/graphics/alchemy/default.nix
index ee8543f7039a..263c411a8dbf 100644
--- a/pkgs/applications/graphics/alchemy/default.nix
+++ b/pkgs/applications/graphics/alchemy/default.nix
@@ -10,7 +10,7 @@ stdenv.mkDerivation {
   };
 
   installPhase = ''
-    ensureDir $out/bin $out/share
+    mkdir -p $out/bin $out/share
     cp -a . $out/share/alchemy
     cat >> $out/bin/alchemy << EOF
     #!/bin/sh
diff --git a/pkgs/applications/misc/keepass/default.nix b/pkgs/applications/misc/keepass/default.nix
index 0098e626b424..89f794850d27 100644
--- a/pkgs/applications/misc/keepass/default.nix
+++ b/pkgs/applications/misc/keepass/default.nix
@@ -24,12 +24,12 @@ stdenv.mkDerivation rec {
 
 
   installPhase = ''
-    ensureDir "$out/bin"
+    mkdir -p "$out/bin"
     echo "${mono}/bin/mono $out/KeePass.exe" > $out/bin/keepass
     chmod +x $out/bin/keepass
     echo $out
     cp -r ./* $out/
-    ensureDir "$out/share/applications"
+    mkdir -p "$out/share/applications"
     cp ${desktopItem}/share/applications/* $out/share/applications
   '';
 
diff --git a/pkgs/applications/misc/librecad/2.0.nix b/pkgs/applications/misc/librecad/2.0.nix
index 2f140db93973..f7743feddbb2 100644
--- a/pkgs/applications/misc/librecad/2.0.nix
+++ b/pkgs/applications/misc/librecad/2.0.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out/bin $out/share
+    mkdir -p $out/bin $out/share
     cp -R unix/librecad $out/bin
     cp -R unix/resources $out/share/librecad
   '';
diff --git a/pkgs/applications/misc/librecad/default.nix b/pkgs/applications/misc/librecad/default.nix
index b225519f4868..6e368f6fb10d 100644
--- a/pkgs/applications/misc/librecad/default.nix
+++ b/pkgs/applications/misc/librecad/default.nix
@@ -17,7 +17,7 @@ stdenv.mkDerivation {
   configurePhase = "qmake PREFIX=$out";
 
   installPhase = ''
-    ensureDir $out/bin $out/share
+    mkdir -p $out/bin $out/share
     cp -R unix/librecad $out/bin
     cp -R unix/resources $out/share/librecad
   '';
diff --git a/pkgs/applications/misc/synergy/default.nix b/pkgs/applications/misc/synergy/default.nix
index 834b514148b6..d975d171518d 100644
--- a/pkgs/applications/misc/synergy/default.nix
+++ b/pkgs/applications/misc/synergy/default.nix
@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
   # http://synergy-foss.org/spit/issues/details/3317/
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp ../bin/synergyc $out/bin
     cp ../bin/synergys $out/bin
     cp ../bin/synergyd $out/bin
diff --git a/pkgs/applications/misc/vanitygen/default.nix b/pkgs/applications/misc/vanitygen/default.nix
index e16767d4c261..99b0e70c898f 100644
--- a/pkgs/applications/misc/vanitygen/default.nix
+++ b/pkgs/applications/misc/vanitygen/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ openssl pcre ];
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp vanitygen $out/bin
     cp keyconv $out/bin/vanitygen-keyconv
   '';
diff --git a/pkgs/applications/networking/bittorrentsync/default.nix b/pkgs/applications/networking/bittorrentsync/default.nix
index abb94a32bd71..989ceb235b02 100644
--- a/pkgs/applications/networking/bittorrentsync/default.nix
+++ b/pkgs/applications/networking/bittorrentsync/default.nix
@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ patchelf ];
 
   installPhase = ''
-    ensureDir "$out/bin/"
+    mkdir -p "$out/bin/"
     cp -r "btsync" "$out/bin/"
 
     patchelf --interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" \
diff --git a/pkgs/applications/networking/browsers/chromium/browser.nix b/pkgs/applications/networking/browsers/chromium/browser.nix
index d425c3f07384..ffc23a9d968d 100644
--- a/pkgs/applications/networking/browsers/chromium/browser.nix
+++ b/pkgs/applications/networking/browsers/chromium/browser.nix
@@ -8,7 +8,7 @@ mkChromiumDerivation (base: rec {
   buildTargets = [ "mksnapshot" "chrome" ];
 
   installPhase = ''
-    ensureDir "$libExecPath"
+    mkdir -p "$libExecPath"
     cp -v "$buildPath/"*.pak "$libExecPath/"
     cp -v "$buildPath/icudtl.dat" "$libExecPath/"
     cp -vLR "$buildPath/locales" "$buildPath/resources" "$libExecPath/"
diff --git a/pkgs/applications/networking/browsers/chromium/default.nix b/pkgs/applications/networking/browsers/chromium/default.nix
index 44fd3c69e537..4dfdca882bc8 100644
--- a/pkgs/applications/networking/browsers/chromium/default.nix
+++ b/pkgs/applications/networking/browsers/chromium/default.nix
@@ -67,7 +67,7 @@ in stdenv.mkDerivation {
     browserBinary = "${chromium.browser}/libexec/chromium/chromium";
     sandboxBinary = "${chromium.sandbox}/bin/chromium-sandbox";
   in ''
-    ensureDir "$out/bin" "$out/share/applications"
+    mkdir -p "$out/bin" "$out/share/applications"
 
     ln -s "${chromium.browser}/share" "$out/share"
     makeWrapper "${browserBinary}" "$out/bin/chromium" \
diff --git a/pkgs/applications/networking/browsers/chromium/plugins.nix b/pkgs/applications/networking/browsers/chromium/plugins.nix
index f760b06fe24b..e0c45f910751 100644
--- a/pkgs/applications/networking/browsers/chromium/plugins.nix
+++ b/pkgs/applications/networking/browsers/chromium/plugins.nix
@@ -22,7 +22,7 @@ let
         else if source.channel == "stable" then "chrome"
         else "chrome-${source.channel}";
     in ''
-      ensureDir plugins
+      mkdir -p plugins
       ar p "$src" data.tar.lzma | tar xJ -C plugins --strip-components=4 \
         ./opt/google/${chan}/PepperFlash \
         ./opt/google/${chan}/libpdf.so
@@ -53,7 +53,7 @@ let
       pdfInfo = "#${pdfName}#${pdfDescription};${pdfMimeTypes}";
     in ''
       install -vD libpdf.so "$pdf/lib/libpdf.so"
-      ensureDir "$pdf/nix-support"
+      mkdir -p "$pdf/nix-support"
       echo "--register-pepper-plugins='$pdf/lib/libpdf.so${pdfInfo}'" \
         > "$pdf/nix-support/chromium-flags"
 
@@ -63,7 +63,7 @@ let
 
       install -vD PepperFlash/libpepflashplayer.so \
         "$flash/lib/libpepflashplayer.so"
-      ensureDir "$flash/nix-support"
+      mkdir -p "$flash/nix-support"
       echo "--ppapi-flash-path='$flash/lib/libpepflashplayer.so'" \
            "--ppapi-flash-version=$flashVersion" \
            > "$flash/nix-support/chromium-flags"
diff --git a/pkgs/applications/networking/browsers/chromium/source/default.nix b/pkgs/applications/networking/browsers/chromium/source/default.nix
index 6a6b299ee511..0d8a4156703e 100644
--- a/pkgs/applications/networking/browsers/chromium/source/default.nix
+++ b/pkgs/applications/networking/browsers/chromium/source/default.nix
@@ -44,7 +44,7 @@ stdenv.mkDerivation {
 
   outputs = [ "out" "sandbox" "bundled" "main" ];
   installPhase = ''
-    ensureDir "$out" "$sandbox" "$bundled" "$main"
+    mkdir -p "$out" "$sandbox" "$bundled" "$main"
 
     header "copying browser main sources to $main"
     find . -mindepth 1 -maxdepth 1 \
diff --git a/pkgs/applications/networking/dropbox-cli/default.nix b/pkgs/applications/networking/dropbox-cli/default.nix
index 5262c121bb28..51f3ae2ac8d9 100644
--- a/pkgs/applications/networking/dropbox-cli/default.nix
+++ b/pkgs/applications/networking/dropbox-cli/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation {
   phases = "unpackPhase installPhase";
 
   installPhase = ''
-    ensureDir "$out/bin/" "$out/share/applications"
+    mkdir -p "$out/bin/" "$out/share/applications"
     cp data/dropbox.desktop "$out/share/applications"
     substitute "dropbox.in" "$out/bin/dropbox" \
       --replace '@PACKAGE_VERSION@' ${version} \
diff --git a/pkgs/applications/networking/dropbox/default.nix b/pkgs/applications/networking/dropbox/default.nix
index 62dce4c42127..55b7bd7486b4 100644
--- a/pkgs/applications/networking/dropbox/default.nix
+++ b/pkgs/applications/networking/dropbox/default.nix
@@ -70,9 +70,9 @@ in stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir "$out/${appdir}"
+    mkdir -p "$out/${appdir}"
     cp -r ".dropbox-dist/"* "$out/${appdir}/"
-    ensureDir "$out/bin"
+    mkdir -p "$out/bin"
     ln -s "$out/${appdir}/dropbox" "$out/bin/dropbox"
 
     patchelf --set-interpreter ${stdenv.glibc}/lib/${interpreter} \
@@ -83,7 +83,7 @@ in stdenv.mkDerivation {
     find "$out/${appdir}" -type f -a -perm +0100 \
       -print -exec patchelf --force-rpath --set-rpath "$RPATH" {} \;
 
-    ensureDir "$out/share/applications"
+    mkdir -p "$out/share/applications"
     cp "${desktopItem}/share/applications/"* $out/share/applications
   '';
 
diff --git a/pkgs/applications/networking/instant-messengers/pidgin-plugins/skype4pidgin/default.nix b/pkgs/applications/networking/instant-messengers/pidgin-plugins/skype4pidgin/default.nix
index 544aa06877ad..339e36321b33 100644
--- a/pkgs/applications/networking/instant-messengers/pidgin-plugins/skype4pidgin/default.nix
+++ b/pkgs/applications/networking/instant-messengers/pidgin-plugins/skype4pidgin/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   buildPhase  = "make libskype.so libskype_dbus.so";
 
   installPhase = ''
-    ensureDir $out/pixmaps/pidgin/protocols/{16,22,48} $out/bin $out/lib/pidgin
+    mkdir -p $out/pixmaps/pidgin/protocols/{16,22,48} $out/bin $out/lib/pidgin
     cp icons/16/skypeout.png $out/pixmaps/pidgin/protocols/16
     cp icons/22/skypeout.png $out/pixmaps/pidgin/protocols/22
     cp icons/48/skypeout.png $out/pixmaps/pidgin/protocols/48
diff --git a/pkgs/applications/networking/irc/irssi/fish/default.nix b/pkgs/applications/networking/irc/irssi/fish/default.nix
index 98d5afa0ba9f..2471c4885af8 100644
--- a/pkgs/applications/networking/irc/irssi/fish/default.nix
+++ b/pkgs/applications/networking/irc/irssi/fish/default.nix
@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/lib/irssi/modules
+    mkdir -p $out/lib/irssi/modules
     cp src/.libs/libfish.so $out/lib/irssi/modules
   '';
   
diff --git a/pkgs/applications/networking/p2p/freenet/default.nix b/pkgs/applications/networking/p2p/freenet/default.nix
index 4c74c2c32de0..cb53f4b5aa31 100644
--- a/pkgs/applications/networking/p2p/freenet/default.nix
+++ b/pkgs/applications/networking/p2p/freenet/default.nix
@@ -34,7 +34,7 @@ stdenv.mkDerivation {
   buildPhase = "ant package-only";
 
   installPhase = ''
-    ensureDir $out/share/freenet $out/bin
+    mkdir -p $out/share/freenet $out/bin
     cp lib/bcprov.jar $out/share/freenet
     cp lib/freenet/freenet-ext.jar $out/share/freenet
     cp dist/freenet.jar $out/share/freenet
diff --git a/pkgs/applications/networking/syncthing/default.nix b/pkgs/applications/networking/syncthing/default.nix
index 8f169180dd5e..226b7f6d097b 100644
--- a/pkgs/applications/networking/syncthing/default.nix
+++ b/pkgs/applications/networking/syncthing/default.nix
@@ -31,7 +31,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp -r ./bin $out
   '';
 
diff --git a/pkgs/applications/office/zotero/default.nix b/pkgs/applications/office/zotero/default.nix
index f0f7d801d8fd..b6636cef6418 100644
--- a/pkgs/applications/office/zotero/default.nix
+++ b/pkgs/applications/office/zotero/default.nix
@@ -23,10 +23,10 @@ stdenv.mkDerivation {
 
   inherit bash xulrunner;
   installPhase = ''
-    ensureDir "$out/libexec/zotero"
+    mkdir -p "$out/libexec/zotero"
     cp -vR * "$out/libexec/zotero/"
 
-    ensureDir "$out/bin"
+    mkdir -p "$out/bin"
     substituteAll "${./zotero.sh}" "$out/bin/zotero"
     chmod +x "$out/bin/zotero"
   '';
diff --git a/pkgs/applications/science/math/gap/default.nix b/pkgs/applications/science/math/gap/default.nix
index f76640567f60..e7766fab5815 100644
--- a/pkgs/applications/science/math/gap/default.nix
+++ b/pkgs/applications/science/math/gap/default.nix
@@ -38,7 +38,7 @@ rec {
   phaseNames = ["doConfigure" "doMake" "doDeploy"];
 
   doDeploy = a.fullDepEntry ''
-    ensureDir "$out/bin" "$out/share/gap/"
+    mkdir -p "$out/bin" "$out/share/gap/"
 
     cp -r . "$out/share/gap/build-dir"
 
diff --git a/pkgs/applications/version-management/git-and-tools/git-bz/default.nix b/pkgs/applications/version-management/git-and-tools/git-bz/default.nix
index 3a2270cf972d..4c4ff62901e5 100644
--- a/pkgs/applications/version-management/git-and-tools/git-bz/default.nix
+++ b/pkgs/applications/version-management/git-and-tools/git-bz/default.nix
@@ -21,8 +21,8 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out
-    ensureDir $out/bin
+    mkdir -p $out
+    mkdir -p $out/bin
     cp git-bz $out/bin
     wrapProgram $out/bin/git-bz \
       --prefix PYTHONPATH : "$(toPythonPath $python):$(toPythonPath $pysqlite)"
diff --git a/pkgs/applications/version-management/git-and-tools/svn2git-kde/default.nix b/pkgs/applications/version-management/git-and-tools/svn2git-kde/default.nix
index c44f2dbcbb6b..94c819e711b5 100644
--- a/pkgs/applications/version-management/git-and-tools/svn2git-kde/default.nix
+++ b/pkgs/applications/version-management/git-and-tools/svn2git-kde/default.nix
@@ -16,7 +16,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp svn-all-fast-export $out/bin
   '';
 
diff --git a/pkgs/applications/video/makemkv/builder.sh b/pkgs/applications/video/makemkv/builder.sh
index 0e1898a45564..e4cfcf3d9068 100644
--- a/pkgs/applications/video/makemkv/builder.sh
+++ b/pkgs/applications/video/makemkv/builder.sh
@@ -30,9 +30,9 @@ for i in ${bin} ; do
     ${i}
 done 
 
-ensureDir $out/bin
-ensureDir $out/lib
-ensureDir $out/share/MakeMKV
+mkdir -p $out/bin
+mkdir -p $out/lib
+mkdir -p $out/share/MakeMKV
 cp ${lib} ${out}/lib
 cp ${bin} ${out}/bin
 cp makemkv-bin-${ver}/src/share/* $out/share/MakeMKV
diff --git a/pkgs/applications/video/omxplayer/default.nix b/pkgs/applications/video/omxplayer/default.nix
index b3880067cac4..6bc982efa128 100644
--- a/pkgs/applications/video/omxplayer/default.nix
+++ b/pkgs/applications/video/omxplayer/default.nix
@@ -71,7 +71,7 @@ stdenv.mkDerivation rec {
     export INCLUDES="-I${raspberrypifw}/include/interface/vcos/pthreads -I${raspberrypifw}/include/interface/vmcs_host/linux/"
   '';
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp omxplayer.bin $out/bin
   '';
   buildInputs = [ raspberrypifw ffmpeg pcre boostHeaders freetype zlib ];
diff --git a/pkgs/build-support/cabal/default.nix b/pkgs/build-support/cabal/default.nix
index bc73d1f73a2b..67934ed0c291 100644
--- a/pkgs/build-support/cabal/default.nix
+++ b/pkgs/build-support/cabal/default.nix
@@ -250,12 +250,12 @@ assert !enableStaticLibraries -> versionOlder "7.7" ghc.version;
 
               ./Setup copy
 
-              ensureDir $out/bin # necessary to get it added to PATH
+              mkdir -p $out/bin # necessary to get it added to PATH
 
               local confDir=$out/lib/ghc-${ghc.ghc.version}/package.conf.d
               local installedPkgConf=$confDir/${self.fname}.installedconf
               local pkgConf=$confDir/${self.fname}.conf
-              ensureDir $confDir
+              mkdir -p $confDir
               ./Setup register --gen-pkg-config=$pkgConf
               if test -f $pkgConf; then
                 echo '[]' > $installedPkgConf
diff --git a/pkgs/build-support/kdewrapper/default.nix b/pkgs/build-support/kdewrapper/default.nix
index 6dcf68a324a2..64dfd7d0ca6b 100644
--- a/pkgs/build-support/kdewrapper/default.nix
+++ b/pkgs/build-support/kdewrapper/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation {
   inherit libs;
 
   buildCommand = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
 
     KDEDIRS=${program}
     QT_PLUGIN_PATH=${program}/lib/qt4/plugins:${program}/lib/kde4/plugins
diff --git a/pkgs/build-support/make-startupitem/default.nix b/pkgs/build-support/make-startupitem/default.nix
index dc78b8a704e2..fad6f00d8211 100644
--- a/pkgs/build-support/make-startupitem/default.nix
+++ b/pkgs/build-support/make-startupitem/default.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation {
   priority = 5;
 
   buildCommand = ''
-    ensureDir $out/share/autostart
+    mkdir -p $out/share/autostart
     target=${name}.desktop
     cp ${package}/share/applications/${srcPrefix}${name}.desktop $target
     chmod +rw $target
diff --git a/pkgs/build-support/release/functions.sh b/pkgs/build-support/release/functions.sh
index 9f2d03519c8c..8ac67a196721 100644
--- a/pkgs/build-support/release/functions.sh
+++ b/pkgs/build-support/release/functions.sh
@@ -9,6 +9,6 @@ findTarballs() {
 }
 
 propagateImageName() {
-    ensureDir $out/nix-support
+    mkdir -p $out/nix-support
     cat "$diskImage"/nix-support/full-name > $out/nix-support/full-name
 }
diff --git a/pkgs/build-support/vm/windows/bootstrap.nix b/pkgs/build-support/vm/windows/bootstrap.nix
index e3b44d1b6ab7..ebea819b1910 100644
--- a/pkgs/build-support/vm/windows/bootstrap.nix
+++ b/pkgs/build-support/vm/windows/bootstrap.nix
@@ -69,7 +69,7 @@ in rec {
         -b "${installedVM}/disk.img" \
         -f qcow2 winvm.img
       ${runAndSuspend}
-      ensureDir "$out"
+      mkdir -p "$out"
       cp winvm.img "$out/disk.img"
       cp state.gz "$out/state.gz"
     '';
diff --git a/pkgs/build-support/vm/windows/install/default.nix b/pkgs/build-support/vm/windows/install/default.nix
index 10690bf6b287..fe8e8f61de02 100644
--- a/pkgs/build-support/vm/windows/install/default.nix
+++ b/pkgs/build-support/vm/windows/install/default.nix
@@ -22,7 +22,7 @@ let
   cygwinSshKey = stdenv.mkDerivation {
     name = "snakeoil-ssh-cygwin";
     buildCommand = ''
-      ensureDir "$out"
+      mkdir -p "$out"
       ${openssh}/bin/ssh-keygen -t ecdsa -f "$out/key" -N ""
     '';
   };
@@ -65,7 +65,7 @@ in stdenv.mkDerivation {
   buildCommand = ''
     ${qemu}/bin/qemu-img create -f qcow2 winvm.img 2G
     ${installController}
-    ensureDir "$out"
+    mkdir -p "$out"
     cp winvm.img "$out/disk.img"
   '';
   passthru = {
diff --git a/pkgs/data/misc/tzdata/default.nix b/pkgs/data/misc/tzdata/default.nix
index afee316d0bf8..71153d884991 100644
--- a/pkgs/data/misc/tzdata/default.nix
+++ b/pkgs/data/misc/tzdata/default.nix
@@ -27,7 +27,7 @@ stdenv.mkDerivation rec {
       ln -s . $out/share/zoneinfo/posix
       mv $out/share/zoneinfo-leaps $out/share/zoneinfo/right
 
-      ensureDir "$lib/include"
+      mkdir -p "$lib/include"
       cp tzfile.h "$lib/include/tzfile.h"
     '';
 
diff --git a/pkgs/development/compilers/ghdl/default.nix b/pkgs/development/compilers/ghdl/default.nix
index cd33d3d79a70..7b103805def3 100644
--- a/pkgs/development/compilers/ghdl/default.nix
+++ b/pkgs/development/compilers/ghdl/default.nix
@@ -34,14 +34,14 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp ghdl_mcode $out/bin
 
-    ensureDir $out/share/ghdl_mcode/translate
+    mkdir -p $out/share/ghdl_mcode/translate
     cp -R ../lib $out/share/ghdl_mcode/translate
     cp -R ../../libraries $out/share/ghdl_mcode
 
-    ensureDir $out/share/man/man1
+    mkdir -p $out/share/man/man1
     cp ../../doc/ghdl.1 $out/share/man/man1/ghdl_mcode.1
 
     # Ghdl has some timestamps checks, storing file timestamps in '.cf' files.
diff --git a/pkgs/development/compilers/gwt/2.4.0.nix b/pkgs/development/compilers/gwt/2.4.0.nix
index 65208b062c25..f0dc9378c4f0 100644
--- a/pkgs/development/compilers/gwt/2.4.0.nix
+++ b/pkgs/development/compilers/gwt/2.4.0.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation {
   buildInputs = [ unzip ];
 
   installPhase = ''
-    ensureDir $out
+    mkdir -p $out
     unzip $src
     mv gwt-2.4.0 $out/bin
   '';
diff --git a/pkgs/development/compilers/mercury/default.nix b/pkgs/development/compilers/mercury/default.nix
index 5ea922a371a7..21af582c594b 100644
--- a/pkgs/development/compilers/mercury/default.nix
+++ b/pkgs/development/compilers/mercury/default.nix
@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
   '';
 
   preConfigure = ''
-    ensureDir $out/lib/mercury/cgi-bin ;
+    mkdir -p $out/lib/mercury/cgi-bin ;
     configureFlags="--enable-deep-profiler=$out/lib/mercury/cgi-bin";
   '';
 
diff --git a/pkgs/development/compilers/ocaml/3.11.2.nix b/pkgs/development/compilers/ocaml/3.11.2.nix
index cffd7c3f54a4..64cf8a9f9f7b 100644
--- a/pkgs/development/compilers/ocaml/3.11.2.nix
+++ b/pkgs/development/compilers/ocaml/3.11.2.nix
@@ -37,7 +37,7 @@ stdenv.mkDerivation rec {
     patch -p0 < ${./mips64.patch}
   '';
   postBuild = ''
-    ensureDir $out/include
+    mkdir -p $out/include
     ln -sv $out/lib/ocaml/caml $out/include/caml
   '';
 
diff --git a/pkgs/development/compilers/pakcs/default.nix b/pkgs/development/compilers/pakcs/default.nix
index 60071a8f6fa9..1fb4318ebb92 100644
--- a/pkgs/development/compilers/pakcs/default.nix
+++ b/pkgs/development/compilers/pakcs/default.nix
@@ -54,13 +54,13 @@ stdenv.mkDerivation rec {
     export LC_ALL=en_US.UTF-8
 
     # Set up link to cymake, which has been built already.
-    ensureDir bin/.local
+    mkdir -p bin/.local
     ln -s ${curryFront}/bin/cymake bin/.local/
   '';
 
   installPhase = ''
     # Prepare PAKCSHOME directory.
-    ensureDir $out/pakcs
+    mkdir -p $out/pakcs
     for d in bin curry2prolog currytools lib tools cpns include www examples docs ; do
       cp -r $d $out/pakcs ;
     done
@@ -80,7 +80,7 @@ stdenv.mkDerivation rec {
     (cd $out/pakcs/www ; make)
 
     # Install bin.
-    ensureDir $out/bin
+    mkdir -p $out/bin
     for b in makecurrycgi .makesavedstate pakcs parsecurry cleancurry \
              addtypes cass currybrowse currycreatemake currydoc currytest \
              dataToXml erd2curry ; do
@@ -88,7 +88,7 @@ stdenv.mkDerivation rec {
     done
 
     # Place emacs lisp files in expected locations.
-    ensureDir $out/share/emacs/site-lisp/curry-pakcs
+    mkdir -p $out/share/emacs/site-lisp/curry-pakcs
     for e in "tools/emacs/"*.el ; do
       cp $e $out/share/emacs/site-lisp/curry-pakcs/ ;
     done
diff --git a/pkgs/development/libraries/aacskeys/default.nix b/pkgs/development/libraries/aacskeys/default.nix
index 088f2cc4b1e0..0b20d8a41ea1 100644
--- a/pkgs/development/libraries/aacskeys/default.nix
+++ b/pkgs/development/libraries/aacskeys/default.nix
@@ -25,7 +25,7 @@ stdenv.mkDerivation {
   buildInputs = [openssl jdk premake3];
 
   installPhase = ''
-    ensureDir $out/{bin,lib,share/${baseName}}
+    mkdir -p $out/{bin,lib,share/${baseName}}
 
     # Install lib
     install -Dm444 lib/linux/libaacskeys.so $out/lib
diff --git a/pkgs/development/libraries/apache-activemq/default.nix b/pkgs/development/libraries/apache-activemq/default.nix
index d55ff9049eda..2f2792dec140 100644
--- a/pkgs/development/libraries/apache-activemq/default.nix
+++ b/pkgs/development/libraries/apache-activemq/default.nix
@@ -12,7 +12,7 @@ stdenv.mkDerivation rec {
   phases = [ "unpackPhase" "installPhase" ];
 
   installPhase = ''
-    ensureDir $out
+    mkdir -p $out
     mv * $out/
     for j in `find $out/lib -name "*.jar"`; do
       cp="''${cp:+"$cp:"}$j";
diff --git a/pkgs/development/libraries/bwidget/default.nix b/pkgs/development/libraries/bwidget/default.nix
index 81f4f9a287ec..0d1913bc8e7a 100644
--- a/pkgs/development/libraries/bwidget/default.nix
+++ b/pkgs/development/libraries/bwidget/default.nix
@@ -12,7 +12,7 @@ stdenv.mkDerivation rec {
   dontBuild = true;
 
   installPhase = ''
-    ensureDir "$out/lib/${passthru.libPrefix}"
+    mkdir -p "$out/lib/${passthru.libPrefix}"
     cp -R *.tcl lang images "$out/lib/${passthru.libPrefix}"
   '';
 
diff --git a/pkgs/development/libraries/haskell/ghc-heap-view/default.nix b/pkgs/development/libraries/haskell/ghc-heap-view/default.nix
index 679ced622d9b..38220eeb05ea 100644
--- a/pkgs/development/libraries/haskell/ghc-heap-view/default.nix
+++ b/pkgs/development/libraries/haskell/ghc-heap-view/default.nix
@@ -6,7 +6,7 @@ cabal.mkDerivation (self: {
   sha256 = "1qi7f3phj2j63x1wd2cvk36945cxd84s12zs03hlrn49wzx2pf1n";
   buildDepends = [ binary transformers ];
   postInstall = ''
-    ensureDir "$out/share/ghci"
+    mkdir -p "$out/share/ghci"
     ln -s "$out/share/$pname-$version/ghci" "$out/share/ghci/$pname"
   '';
   meta = {
diff --git a/pkgs/development/libraries/haskell/ghc-mod/default.nix b/pkgs/development/libraries/haskell/ghc-mod/default.nix
index f05bfedafcff..31d1d7689b1e 100644
--- a/pkgs/development/libraries/haskell/ghc-mod/default.nix
+++ b/pkgs/development/libraries/haskell/ghc-mod/default.nix
@@ -24,7 +24,7 @@ cabal.mkDerivation (self: {
     make
     rm Makefile
     cd ..
-    ensureDir "$out/share/emacs"
+    mkdir -p "$out/share/emacs"
     mv $pname-$version emacs/site-lisp
 
     mv $out/bin/ghc-mod $out/bin/.ghc-mod-wrapped
diff --git a/pkgs/development/libraries/haskell/ghc-vis/default.nix b/pkgs/development/libraries/haskell/ghc-vis/default.nix
index a15ed9d1c47c..d8edd81cda65 100644
--- a/pkgs/development/libraries/haskell/ghc-vis/default.nix
+++ b/pkgs/development/libraries/haskell/ghc-vis/default.nix
@@ -12,7 +12,7 @@ cabal.mkDerivation (self: {
   ];
   jailbreak = true;
   postInstall = ''
-    ensureDir "$out/share/ghci"
+    mkdir -p "$out/share/ghci"
     ln -s "$out/share/$pname-$version/ghci" "$out/share/ghci/$pname"
   '';
   meta = {
diff --git a/pkgs/development/libraries/haskell/hoogle/local.nix b/pkgs/development/libraries/haskell/hoogle/local.nix
index 67f38f260e07..eebfd0224d26 100644
--- a/pkgs/development/libraries/haskell/hoogle/local.nix
+++ b/pkgs/development/libraries/haskell/hoogle/local.nix
@@ -65,7 +65,7 @@ cabal.mkDerivation (self: rec {
         exit 1
     fi
 
-    ensureDir $out/share/hoogle/doc
+    mkdir -p $out/share/hoogle/doc
     export HOOGLE_DOC_PATH=$out/share/hoogle/doc
 
     cd $out/share/hoogle
diff --git a/pkgs/development/mobile/androidenv/androidsdk.nix b/pkgs/development/mobile/androidenv/androidsdk.nix
index 1a2124754a20..3c9327f1c594 100644
--- a/pkgs/development/mobile/androidenv/androidsdk.nix
+++ b/pkgs/development/mobile/androidenv/androidsdk.nix
@@ -178,7 +178,7 @@ stdenv.mkDerivation rec {
     
     # Create wrappers to the most important tools and platform tools so that we can run them if the SDK is in our PATH
     
-    ensureDir $out/bin
+    mkdir -p $out/bin
 
     for i in $out/libexec/android-sdk-*/tools/*
     do
diff --git a/pkgs/development/mobile/xcodeenv/simulate-app.nix b/pkgs/development/mobile/xcodeenv/simulate-app.nix
index d25ef0f8e431..c999497d8c09 100644
--- a/pkgs/development/mobile/xcodeenv/simulate-app.nix
+++ b/pkgs/development/mobile/xcodeenv/simulate-app.nix
@@ -10,7 +10,7 @@ in
 stdenv.mkDerivation {
   name = stdenv.lib.replaceChars [" "] [""] name;
   buildCommand = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cat > $out/bin/run-test-simulator << "EOF"
     #! ${stdenv.shell} -e
 
diff --git a/pkgs/development/mobile/xcodeenv/xcodewrapper.nix b/pkgs/development/mobile/xcodeenv/xcodewrapper.nix
index 71e34ee5127d..fd375d6213c6 100644
--- a/pkgs/development/mobile/xcodeenv/xcodewrapper.nix
+++ b/pkgs/development/mobile/xcodeenv/xcodewrapper.nix
@@ -3,7 +3,7 @@
 stdenv.mkDerivation {
   name = "xcode-wrapper-"+version;
   buildCommand = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cd $out/bin
     ln -s /usr/bin/xcode-select
     ln -s /usr/bin/xcodebuild
diff --git a/pkgs/development/ocaml-modules/ocamlmake/default.nix b/pkgs/development/ocaml-modules/ocamlmake/default.nix
index 0170119d94e0..3f91901d9b64 100644
--- a/pkgs/development/ocaml-modules/ocamlmake/default.nix
+++ b/pkgs/development/ocaml-modules/ocamlmake/default.nix
@@ -14,7 +14,7 @@ in stdenv.mkDerivation {
   };
 
   installPhase = ''
-    ensureDir "$out/include/"
+    mkdir -p "$out/include/"
     cp OCamlMakefile "$out/include/"
   '';
 
diff --git a/pkgs/development/tools/apktool/default.nix b/pkgs/development/tools/apktool/default.nix
index a415ffd152d7..239416535755 100644
--- a/pkgs/development/tools/apktool/default.nix
+++ b/pkgs/development/tools/apktool/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
 
   installPhase = ''
     install -D apktool.jar "$out/libexec/apktool/apktool.jar"
-    ensureDir "$out/bin"
+    mkdir -p "$out/bin"
     makeWrapper "${jre}/bin/java" "$out/bin/apktool" \
         --add-flags "-jar $out/libexec/apktool/apktool.jar" \
         --prefix PATH : "${buildTools}/build-tools/android-4.3/"
diff --git a/pkgs/development/tools/literate-programming/noweb/default.nix b/pkgs/development/tools/literate-programming/noweb/default.nix
index 291bc29e1b70..4f8691c40adb 100644
--- a/pkgs/development/tools/literate-programming/noweb/default.nix
+++ b/pkgs/development/tools/literate-programming/noweb/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation {
     sha256 = "10hdd6mrk26kyh4bnng4ah5h1pnanhsrhqa7qwqy6dyv3rng44y9";
   };
   preBuild = ''
-    ensureDir $out/lib/noweb
+    mkdir -p $out/lib/noweb
     cd src
     makeFlags="BIN=$out/bin LIB=$out/lib/noweb MAN=$out/share/man TEXINPUTS=$out/share/texmf/tex/latex"
   '';
diff --git a/pkgs/development/tools/misc/distcc/masq.nix b/pkgs/development/tools/misc/distcc/masq.nix
index 117480670c39..753c35b5d3a2 100644
--- a/pkgs/development/tools/misc/distcc/masq.nix
+++ b/pkgs/development/tools/misc/distcc/masq.nix
@@ -5,7 +5,7 @@ stdenv.mkDerivation {
 
   phases = [ "installPhase" ];
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
 
     bin=${gccRaw}/bin
 
diff --git a/pkgs/development/tools/misc/grafana/default.nix b/pkgs/development/tools/misc/grafana/default.nix
index 346c7fb6ad29..b1566684cf0b 100644
--- a/pkgs/development/tools/misc/grafana/default.nix
+++ b/pkgs/development/tools/misc/grafana/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
 
   phases = ["unpackPhase" "installPhase"];
   installPhase = ''
-    ensureDir $out && cp -R * $out
+    mkdir -p $out && cp -R * $out
     ${optionalString (conf!=null) ''cp ${conf} $out/config.js''}
   '';
 
diff --git a/pkgs/development/tools/misc/opengrok/default.nix b/pkgs/development/tools/misc/opengrok/default.nix
index 8f77b3d7283a..d38c862ecfb1 100644
--- a/pkgs/development/tools/misc/opengrok/default.nix
+++ b/pkgs/development/tools/misc/opengrok/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ makeWrapper ];
 
   installPhase = ''
-    ensureDir $out
+    mkdir -p $out
     cp -a * $out/
     substituteInPlace $out/bin/OpenGrok --replace /bin/uname ${coreutils}/bin/uname
     wrapProgram $out/bin/OpenGrok \
diff --git a/pkgs/development/tools/node-webkit/default.nix b/pkgs/development/tools/node-webkit/default.nix
index be125801bd50..1c891ddf8765 100644
--- a/pkgs/development/tools/node-webkit/default.nix
+++ b/pkgs/development/tools/node-webkit/default.nix
@@ -33,8 +33,8 @@ in stdenv.mkDerivation rec {
   installPhase = let
     LD_LIBRARY_PATH = "${nwEnv}/lib:${nwEnv}/lib64:$out/share/node-webkit";
   in ''
-    ensureDir $out/bin
-    ensureDir $out/share/node-webkit
+    mkdir -p $out/bin
+    mkdir -p $out/share/node-webkit
     cp -R * $out/share/node-webkit
 
     ln -s ${udev}/lib/libudev.so $out/share/node-webkit/libudev.so.0
diff --git a/pkgs/development/tools/ocaml/deriving/default.nix b/pkgs/development/tools/ocaml/deriving/default.nix
index d53f41b5da5c..55bbf3748ea9 100644
--- a/pkgs/development/tools/ocaml/deriving/default.nix
+++ b/pkgs/development/tools/ocaml/deriving/default.nix
@@ -52,7 +52,7 @@ versionedDerivation "ocaml-deriving" version {
     # not all tests compile !?
     # (cd tests; make)
 
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp -a lib $out/
     cp -a syntax $out
 
diff --git a/pkgs/development/tools/yuicompressor/default.nix b/pkgs/development/tools/yuicompressor/default.nix
index 5dcc30811e22..1a5485af541d 100644
--- a/pkgs/development/tools/yuicompressor/default.nix
+++ b/pkgs/development/tools/yuicompressor/default.nix
@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
   };
 
   buildCommand = ''
-    ensureDir $out/lib
+    mkdir -p $out/lib
     ln -s $src $out/lib/yuicompressor.jar
   '';
 }
diff --git a/pkgs/games/andyetitmoves/default.nix b/pkgs/games/andyetitmoves/default.nix
index cf3f6e1563b8..ec14325e3d9e 100644
--- a/pkgs/games/andyetitmoves/default.nix
+++ b/pkgs/games/andyetitmoves/default.nix
@@ -38,7 +38,7 @@ stdenv.mkDerivation rec {
   phases = "unpackPhase installPhase";
 
   installPhase = ''
-    ensureDir $out/{opt/andyetitmoves,bin}
+    mkdir -p $out/{opt/andyetitmoves,bin}
     cp -r * $out/opt/andyetitmoves/
 
     fullPath=${stdenv.gcc.gcc}/lib64
diff --git a/pkgs/games/crafty/default.nix b/pkgs/games/crafty/default.nix
index 54deae2ecfe1..0e2796df22d8 100644
--- a/pkgs/games/crafty/default.nix
+++ b/pkgs/games/crafty/default.nix
@@ -621,10 +621,10 @@ stdenv.mkDerivation rec {
            else "make";
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp -p ./crafty $out/bin
 
-    ensureDir $out/share/crafty
+    mkdir -p $out/share/crafty
     cd $out/share/crafty
 
     $out/bin/crafty "books create ${startPgn} 60"
@@ -635,7 +635,7 @@ stdenv.mkDerivation rec {
         $out/bin/crafty "book create enormous.pgn 60"
         rm -f *.001 enormous.pgn
         
-        ensureDir $out/share/crafty/TB
+        mkdir -p $out/share/crafty/TB
         ${stdenv.lib.fold
           (tb: acc: acc + "\nln -s "
                         + toString tb
diff --git a/pkgs/games/gsb/default.nix b/pkgs/games/gsb/default.nix
index 52c3830c22a4..757d3cf7681e 100644
--- a/pkgs/games/gsb/default.nix
+++ b/pkgs/games/gsb/default.nix
@@ -32,8 +32,8 @@ stdenv.mkDerivation rec {
     + ":" + stdenv.gcc.gcc + "/lib64";
 
   installPhase = ''
-    ensureDir $out/libexec/positech/GSB/
-    ensureDir $out/bin
+    mkdir -p $out/libexec/positech/GSB/
+    mkdir -p $out/bin
 
     patchelf \
       --interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" \
diff --git a/pkgs/games/openlierox/default.nix b/pkgs/games/openlierox/default.nix
index 0c7e46ae0740..ede7b6fdac43 100644
--- a/pkgs/games/openlierox/default.nix
+++ b/pkgs/games/openlierox/default.nix
@@ -23,7 +23,7 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out/bin $out/share/OpenLieroX
+    mkdir -p $out/bin $out/share/OpenLieroX
     cp bin/* $out/bin
     cp -R ../share/gamedir/* $out/share/OpenLieroX
   '';
diff --git a/pkgs/games/opentyrian/default.nix b/pkgs/games/opentyrian/default.nix
index 260b146217cc..5e2ecdbcc5c7 100644
--- a/pkgs/games/opentyrian/default.nix
+++ b/pkgs/games/opentyrian/default.nix
@@ -22,9 +22,9 @@ stdenv.mkDerivation rec {
   ";
   buildPhase = "make release";
   installPhase = "
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp ./opentyrian $out/bin
-    ensureDir $out/share/opentyrian/data
+    mkdir -p $out/share/opentyrian/data
     unzip -j $data -d $out/share/opentyrian/data
   ";
 
diff --git a/pkgs/games/vessel/default.nix b/pkgs/games/vessel/default.nix
index 9b9dd6c1f43f..8a92490b6e0c 100644
--- a/pkgs/games/vessel/default.nix
+++ b/pkgs/games/vessel/default.nix
@@ -24,8 +24,8 @@ stdenv.mkDerivation rec {
     + ":" + stdenv.lib.makeLibraryPath [ SDL pulseaudio alsaLib ] ;
 
   installPhase = ''
-    ensureDir $out/libexec/strangeloop/vessel/
-    ensureDir $out/bin
+    mkdir -p $out/libexec/strangeloop/vessel/
+    mkdir -p $out/bin
 
     # allow scripting of the mojoinstaller
     gcc -fPIC -shared -o isatty.so $ld_preload
diff --git a/pkgs/games/worldofgoo/default.nix b/pkgs/games/worldofgoo/default.nix
index 13e7e487c8f0..c39ffb1de058 100644
--- a/pkgs/games/worldofgoo/default.nix
+++ b/pkgs/games/worldofgoo/default.nix
@@ -50,8 +50,8 @@ stdenv.mkDerivation rec {
     + ":" + stdenv.gcc.gcc + "/lib64";
 
   installPhase = ''
-    ensureDir $out/libexec/2dboy/WorldOfGoo/
-    ensureDir $out/bin
+    mkdir -p $out/libexec/2dboy/WorldOfGoo/
+    mkdir -p $out/bin
 
     patchelf --interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" --set-rpath $libPath ./WorldOfGoo.bin64
 
diff --git a/pkgs/misc/emulators/bsod/default.nix b/pkgs/misc/emulators/bsod/default.nix
index 181a89b66677..a6cb42d5c679 100644
--- a/pkgs/misc/emulators/bsod/default.nix
+++ b/pkgs/misc/emulators/bsod/default.nix
@@ -11,7 +11,7 @@ stdenv.mkDerivation {
   buildInputs = [ ncurses ];
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp bsod $out/bin
   '';
 
diff --git a/pkgs/misc/vim-plugins/default.nix b/pkgs/misc/vim-plugins/default.nix
index 976e4dc687f3..4bc9a11a5894 100644
--- a/pkgs/misc/vim-plugins/default.nix
+++ b/pkgs/misc/vim-plugins/default.nix
@@ -89,7 +89,7 @@ let vimHelpTags = ''
 
     installPhase = ''
       target=$out/vim-plugins/$path
-      ensureDir $out/vim-plugins
+      mkdir -p $out/vim-plugins
       cp -r . $target
       ${vimHelpTags}
       vimHelpTags $target
diff --git a/pkgs/os-specific/darwin/xcode/default.nix b/pkgs/os-specific/darwin/xcode/default.nix
index 73585d59c0b3..2a48590154e4 100644
--- a/pkgs/os-specific/darwin/xcode/default.nix
+++ b/pkgs/os-specific/darwin/xcode/default.nix
@@ -31,12 +31,12 @@ in stdenv.mkDerivation rec {
   patches = optional (osxVersion == "10.9") ./gcc-fix-enum-attributes.patch;
 
   installPhase = ''
-    ensureDir "$out/share/sysroot"
+    mkdir -p "$out/share/sysroot"
     cp -a * "$out/share/sysroot/"
     ln -s "$out/share/sysroot/usr/lib" "$out/lib"
     ln -s "$out/share/sysroot/usr/include" "$out/include"
 
-    ensureDir "$toolchain"
+    mkdir -p "$toolchain"
     pushd "$toolchain"
     ${xpwn}/bin/hfsplus "$(dirs +1)/../main.hfs" extractall \
       Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr \
diff --git a/pkgs/os-specific/linux/apparmor/default.nix b/pkgs/os-specific/linux/apparmor/default.nix
index 12173e20f3f9..8048419a93ba 100644
--- a/pkgs/os-specific/linux/apparmor/default.nix
+++ b/pkgs/os-specific/linux/apparmor/default.nix
@@ -48,7 +48,7 @@ stdenv.mkDerivation rec {
     make
     make check
     make install
-    ensureDir $out/lib/perl5/site_perl/
+    mkdir -p $out/lib/perl5/site_perl/
     cp swig/perl/LibAppArmor.pm $out/lib/perl5/site_perl/
     cp swig/perl/LibAppArmor.bs $out/lib/perl5/site_perl/
     # this is automatically copied elsewhere....
diff --git a/pkgs/os-specific/linux/bbswitch/default.nix b/pkgs/os-specific/linux/bbswitch/default.nix
index e12c80e08864..6c7d6d5330e2 100644
--- a/pkgs/os-specific/linux/bbswitch/default.nix
+++ b/pkgs/os-specific/linux/bbswitch/default.nix
@@ -22,10 +22,10 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out/lib/modules/${kernel.modDirVersion}/misc
+    mkdir -p $out/lib/modules/${kernel.modDirVersion}/misc
     cp bbswitch.ko $out/lib/modules/${kernel.modDirVersion}/misc
 
-    ensureDir $out/bin
+    mkdir -p $out/bin
     tee $out/bin/discrete_vga_poweroff << EOF
     #!/bin/sh
 
diff --git a/pkgs/os-specific/linux/frandom/default.nix b/pkgs/os-specific/linux/frandom/default.nix
index 419207882f83..1814a72667a6 100644
--- a/pkgs/os-specific/linux/frandom/default.nix
+++ b/pkgs/os-specific/linux/frandom/default.nix
@@ -20,10 +20,10 @@ stdenv.mkDerivation rec {
  
   installPhase = ''
     kernelVersion=${kernel.modDirVersion}
-    ensureDir $out/lib/modules/$kernelVersion/misc
+    mkdir -p $out/lib/modules/$kernelVersion/misc
     cp frandom.ko $out/lib/modules/$kernelVersion/misc
 
-    ensureDir $out/lib/udev/rules.d
+    mkdir -p $out/lib/udev/rules.d
     tee $out/lib/udev/rules.d/10-frandom.rules <<-EOF
     #
     # These are the rules for the frandom devices. In theory, we could let
diff --git a/pkgs/os-specific/linux/gogoclient/default.nix b/pkgs/os-specific/linux/gogoclient/default.nix
index 09a449bbede9..a627a8cbcc94 100644
--- a/pkgs/os-specific/linux/gogoclient/default.nix
+++ b/pkgs/os-specific/linux/gogoclient/default.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
   buildInputs = [openssl];
 
   preFixup = ''
-    ensureDir $out/share/${name}
+    mkdir -p $out/share/${name}
     chmod 444 $out/bin/gogoc.conf
     mv $out/bin/gogoc.conf $out/share/${name}/gogoc.conf.sample
     rm $out/bin/gogoc.conf.sample
diff --git a/pkgs/os-specific/linux/google-authenticator/default.nix b/pkgs/os-specific/linux/google-authenticator/default.nix
index a9278f0c7ce0..7667b330f231 100644
--- a/pkgs/os-specific/linux/google-authenticator/default.nix
+++ b/pkgs/os-specific/linux/google-authenticator/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin $out/lib/security
+    mkdir -p $out/bin $out/lib/security
     cp pam_google_authenticator.so $out/lib/security
     cp google-authenticator $out/bin
   '';
diff --git a/pkgs/os-specific/linux/i7z/default.nix b/pkgs/os-specific/linux/i7z/default.nix
index 33ac05aef478..80e43f17b3c6 100644
--- a/pkgs/os-specific/linux/i7z/default.nix
+++ b/pkgs/os-specific/linux/i7z/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/sbin
+    mkdir -p $out/sbin
     make install prefix=$out
     install -Dm755 GUI/i7z_GUI $out/sbin/i7z-gui
   '';
diff --git a/pkgs/os-specific/linux/mcelog/default.nix b/pkgs/os-specific/linux/mcelog/default.nix
index 5c36bb097812..463722d2c961 100644
--- a/pkgs/os-specific/linux/mcelog/default.nix
+++ b/pkgs/os-specific/linux/mcelog/default.nix
@@ -26,7 +26,7 @@ in stdenv.mkDerivation {
   makeFlags = "prefix=$(out) etcprefix=$(out) DOCDIR=$(out)/share/doc";
 
   preInstall = ''
-    ensureDir $out/share/doc
+    mkdir -p $out/share/doc
   '';
 
   meta = {
diff --git a/pkgs/os-specific/linux/microcode/converter.nix b/pkgs/os-specific/linux/microcode/converter.nix
index 49babc6ca57b..da4d96772171 100644
--- a/pkgs/os-specific/linux/microcode/converter.nix
+++ b/pkgs/os-specific/linux/microcode/converter.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir "$out/bin"
+    mkdir -p "$out/bin"
     cp intel-microcode2ucode "$out/bin/"
   '';
 
diff --git a/pkgs/os-specific/linux/netatop/default.nix b/pkgs/os-specific/linux/netatop/default.nix
index a863ee8a4d04..e1cdd919e935 100644
--- a/pkgs/os-specific/linux/netatop/default.nix
+++ b/pkgs/os-specific/linux/netatop/default.nix
@@ -22,8 +22,8 @@ stdenv.mkDerivation {
   '';
 
   preInstall = ''
-    ensureDir $out/bin $out/sbin $out/share/man/man{4,8}
-    ensureDir $out/lib/modules/${kernel.modDirVersion}/extra
+    mkdir -p $out/bin $out/sbin $out/share/man/man{4,8}
+    mkdir -p $out/lib/modules/${kernel.modDirVersion}/extra
   '';
       
   meta = {
diff --git a/pkgs/os-specific/linux/otpw/default.nix b/pkgs/os-specific/linux/otpw/default.nix
index fe5f938b75b3..c270f0dd0c69 100644
--- a/pkgs/os-specific/linux/otpw/default.nix
+++ b/pkgs/os-specific/linux/otpw/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin $out/lib/security $out/share/man/man{1,8}
+    mkdir -p $out/bin $out/lib/security $out/share/man/man{1,8}
     cp pam_*.so $out/lib/security
     cp otpw-gen $out/bin
     cp *.1 $out/share/man/man1
diff --git a/pkgs/os-specific/linux/rfkill/udev.nix b/pkgs/os-specific/linux/rfkill/udev.nix
index 6cf6e4adfa07..054ed471eaaf 100644
--- a/pkgs/os-specific/linux/rfkill/udev.nix
+++ b/pkgs/os-specific/linux/rfkill/udev.nix
@@ -31,12 +31,12 @@ stdenv.mkDerivation {
   dontBuild = true;
 
   installPhase = ''
-    ensureDir "$out/etc/udev/rules.d/";
+    mkdir -p "$out/etc/udev/rules.d/";
     cat > "$out/etc/udev/rules.d/90-rfkill.rules" << EOF
       SUBSYSTEM=="rfkill", ATTR{type}=="wlan", RUN+="$out/bin/rfkill-hook.sh" 
     EOF
 
-    ensureDir "$out/bin/";
+    mkdir -p "$out/bin/";
     cp ${./rfkill-hook.sh} "$out/bin/rfkill-hook.sh"
     chmod +x "$out/bin/rfkill-hook.sh";
   '';
diff --git a/pkgs/os-specific/linux/x86info/default.nix b/pkgs/os-specific/linux/x86info/default.nix
index 6cd2a431a605..eaec63f98bfc 100644
--- a/pkgs/os-specific/linux/x86info/default.nix
+++ b/pkgs/os-specific/linux/x86info/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ pciutils python ];
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp x86info lsmsr $out/bin
   '';
 
diff --git a/pkgs/servers/dict/dictd-wiktionary.nix b/pkgs/servers/dict/dictd-wiktionary.nix
index 9e9c05d2f915..370bfd39137a 100644
--- a/pkgs/servers/dict/dictd-wiktionary.nix
+++ b/pkgs/servers/dict/dictd-wiktionary.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   builder = writeScript "wiktionary-builder.sh" ''
     source $stdenv/setup
 
-    ensureDir $out/share/dictd/
+    mkdir -p $out/share/dictd/
     cd $out/share/dictd
 
     export LOCALE_ARCHIVE=${glibcLocales}/lib/locale/locale-archive
diff --git a/pkgs/servers/dict/dictd-wordnet.nix b/pkgs/servers/dict/dictd-wordnet.nix
index 063868ddc6e8..b6680e8b21c4 100644
--- a/pkgs/servers/dict/dictd-wordnet.nix
+++ b/pkgs/servers/dict/dictd-wordnet.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
 
   builder = writeScript "builder.sh" ''
     . ${stdenv}/setup
-    ensureDir $out/share/dictd/
+    mkdir -p $out/share/dictd/
     cd $out/share/dictd
 
     for i in ${wordnet}/dict/data.*; do
diff --git a/pkgs/servers/http/thttpd/default.nix b/pkgs/servers/http/thttpd/default.nix
index e03183cbe49d..0bb3d96b37b7 100644
--- a/pkgs/servers/http/thttpd/default.nix
+++ b/pkgs/servers/http/thttpd/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   '';
 
   preInstall = ''
-    ensureDir "$out/man/man1"
+    mkdir -p "$out/man/man1"
     sed -i -e 's/-o bin -g bin *//' Makefile
     sed -i -e '/chgrp/d' extras/Makefile
   '';
diff --git a/pkgs/servers/monitoring/seyren/default.nix b/pkgs/servers/monitoring/seyren/default.nix
index 541c377c4049..e6e151295687 100644
--- a/pkgs/servers/monitoring/seyren/default.nix
+++ b/pkgs/servers/monitoring/seyren/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ makeWrapper jre src ];
 
   installPhase = ''
-    ensureDir "$out"/bin
+    mkdir -p "$out"/bin
     makeWrapper "${jre}/bin/java" "$out"/bin/seyren --add-flags "-jar $src"
   '';
 
diff --git a/pkgs/servers/nosql/influxdb/default.nix b/pkgs/servers/nosql/influxdb/default.nix
index fa9c48c6ea92..77852b6d2ed9 100644
--- a/pkgs/servers/nosql/influxdb/default.nix
+++ b/pkgs/servers/nosql/influxdb/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
     wrapProgram "$out/bin/influxdb" \
         --prefix LD_LIBRARY_PATH : "${stdenv.gcc.gcc}/lib:${stdenv.gcc.gcc}/lib64"
 
-    ensureDir $out/share/influxdb
+    mkdir -p $out/share/influxdb
     cp -R admin scripts config.toml $out/share/influxdb
   '';
 
diff --git a/pkgs/servers/serfdom/default.nix b/pkgs/servers/serfdom/default.nix
index 274fc89f94d0..9274ba86a707 100644
--- a/pkgs/servers/serfdom/default.nix
+++ b/pkgs/servers/serfdom/default.nix
@@ -112,7 +112,7 @@ in
     '';
 
     installPhase = ''
-      ensureDir $out/bin
+      mkdir -p $out/bin
       cp bin/serf $out/bin
     '';
 
diff --git a/pkgs/stdenv/linux/make-bootstrap-tools-crosspi.nix b/pkgs/stdenv/linux/make-bootstrap-tools-crosspi.nix
index 9ea63a46be3e..3abffc469269 100644
--- a/pkgs/stdenv/linux/make-bootstrap-tools-crosspi.nix
+++ b/pkgs/stdenv/linux/make-bootstrap-tools-crosspi.nix
@@ -116,7 +116,7 @@ rec {
 
       buildCommand = ''
 	set -x
-        ensureDir $out/bin $out/lib $out/libexec
+        mkdir -p $out/bin $out/lib $out/libexec
 
         # Copy what we need of Glibc.
         cp -d ${glibc}/lib/ld-*.so* $out/lib
diff --git a/pkgs/tools/backup/store-backup/default.nix b/pkgs/tools/backup/store-backup/default.nix
index e9b98fec7100..c986adeafdcc 100644
--- a/pkgs/tools/backup/store-backup/default.nix
+++ b/pkgs/tools/backup/store-backup/default.nix
@@ -26,7 +26,7 @@ stdenv.mkDerivation {
   };
 
   installPhase = ''
-    ensureDir $out/scripts
+    mkdir -p $out/scripts
     mv * $out
     mv $out/_ATTENTION_ $out/doc
     mv $out/{correct.sh,cron-storebackup} $out/scripts
diff --git a/pkgs/tools/filesystems/unionfs-fuse/default.nix b/pkgs/tools/filesystems/unionfs-fuse/default.nix
index bff5aaf242ba..23340f88376b 100644
--- a/pkgs/tools/filesystems/unionfs-fuse/default.nix
+++ b/pkgs/tools/filesystems/unionfs-fuse/default.nix
@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
   # This must be done in preConfigure because the build process removes
   # helper from the source directory during the build.
   preConfigure = ''
-    ensureDir $out/sbin
+    mkdir -p $out/sbin
     cp -a mount.unionfs $out/sbin/mount.unionfs-fuse
     substituteInPlace $out/sbin/mount.unionfs-fuse --replace mount.fuse ${fuse}/sbin/mount.fuse
     substituteInPlace $out/sbin/mount.unionfs-fuse --replace unionfs $out/bin/unionfs
diff --git a/pkgs/tools/misc/debootstrap/default.nix b/pkgs/tools/misc/debootstrap/default.nix
index aac7855827cc..a76a57864d94 100644
--- a/pkgs/tools/misc/debootstrap/default.nix
+++ b/pkgs/tools/misc/debootstrap/default.nix
@@ -20,7 +20,7 @@ let
     ];
     # TODO install man
     installPhase = ''
-      ensureDir $out/sbin
+      mkdir -p $out/sbin
       ls -l
       t=$out/sbin/MAKEDEV
       cp MAKEDEV $t
@@ -78,7 +78,7 @@ stdenv.mkDerivation {
       functions
 
     d=$out/share/debootstrap
-    ensureDir $out/{share/debootstrap,bin}
+    mkdir -p $out/{share/debootstrap,bin}
 
     ${fakeroot}/bin/fakeroot -- make devices.tar.gz MAKEDEV=${makedev}/sbin/MAKEDEV
 
@@ -94,7 +94,7 @@ stdenv.mkDerivation {
     EOF
     chmod +x $out/bin/debootstrap
 
-    ensureDir $out/man/man8
+    mkdir -p $out/man/man8
     mv debootstrap.8 $out/man/man8
   '';
 
diff --git a/pkgs/tools/misc/megacli/default.nix b/pkgs/tools/misc/megacli/default.nix
index 2b15d4470c36..ef85c3994a8e 100644
--- a/pkgs/tools/misc/megacli/default.nix
+++ b/pkgs/tools/misc/megacli/default.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
        [ stdenv.gcc.gcc stdenv.gcc.libc ncurses ];
 
   buildCommand = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cd $out
     unzip ${src}
     rpm2cpio linux/MegaCli-8.07.07-1.noarch.rpm | cpio -idmv
diff --git a/pkgs/tools/misc/multitail/default.nix b/pkgs/tools/misc/multitail/default.nix
index 96d3764abd46..831bc532c331 100644
--- a/pkgs/tools/misc/multitail/default.nix
+++ b/pkgs/tools/misc/multitail/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation {
   makeFlags = stdenv.lib.optionalString stdenv.isDarwin "-f makefile.macosx";
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp multitail $out/bin
   '';
 
diff --git a/pkgs/tools/misc/picocom/default.nix b/pkgs/tools/misc/picocom/default.nix
index bb08091ad57a..126725eaafcb 100644
--- a/pkgs/tools/misc/picocom/default.nix
+++ b/pkgs/tools/misc/picocom/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
   };
 
   installPhase = ''
-    ensureDir $out/bin $out/share/man/man8
+    mkdir -p $out/bin $out/share/man/man8
     cp picocom $out/bin
     cp picocom.8 $out/share/man/man8
   '';
diff --git a/pkgs/tools/misc/rkflashtool/default.nix b/pkgs/tools/misc/rkflashtool/default.nix
index c985183c1c00..6b74f9ac5d34 100644
--- a/pkgs/tools/misc/rkflashtool/default.nix
+++ b/pkgs/tools/misc/rkflashtool/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp rkunpack rkcrc rkflashtool $out/bin
   '';
 
diff --git a/pkgs/tools/misc/sl/default.nix b/pkgs/tools/misc/sl/default.nix
index 14cc6c4260f7..2ed8d89d43e4 100644
--- a/pkgs/tools/misc/sl/default.nix
+++ b/pkgs/tools/misc/sl/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation {
   buildInputs = [ ncurses ];
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp sl $out/bin
   '';
 
diff --git a/pkgs/tools/networking/connect/default.nix b/pkgs/tools/networking/connect/default.nix
index c6291efad312..8723c53c3229 100644
--- a/pkgs/tools/networking/connect/default.nix
+++ b/pkgs/tools/networking/connect/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
   '';
 
   buildPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     gcc -o $out/bin/connect connect.c
   '';
 
diff --git a/pkgs/tools/networking/filegive/default.nix b/pkgs/tools/networking/filegive/default.nix
index a47a0397bf5a..f9efc6815b67 100644
--- a/pkgs/tools/networking/filegive/default.nix
+++ b/pkgs/tools/networking/filegive/default.nix
@@ -35,7 +35,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp filegive $out/bin
   '';
 
diff --git a/pkgs/tools/networking/reaver-wps/default.nix b/pkgs/tools/networking/reaver-wps/default.nix
index a057985b48cc..65d681fdc224 100644
--- a/pkgs/tools/networking/reaver-wps/default.nix
+++ b/pkgs/tools/networking/reaver-wps/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
   '';
 
   preInstall = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
   '';
 
   meta = {
diff --git a/pkgs/tools/networking/udptunnel/default.nix b/pkgs/tools/networking/udptunnel/default.nix
index 88ee926e4065..0cb777b01af3 100644
--- a/pkgs/tools/networking/udptunnel/default.nix
+++ b/pkgs/tools/networking/udptunnel/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation {
   };
 
   installPhase = ''
-    ensureDir $out/bin $out/share/udptunnel
+    mkdir -p $out/bin $out/share/udptunnel
     cp udptunnel $out/bin
     cp README COPYING* $out/share/udptunnel
   '';
diff --git a/pkgs/tools/security/fprot/default.nix b/pkgs/tools/security/fprot/default.nix
index 2a8531a17954..b43ea402f6dc 100644
--- a/pkgs/tools/security/fprot/default.nix
+++ b/pkgs/tools/security/fprot/default.nix
@@ -11,10 +11,10 @@ stdenv.mkDerivation rec {
   };
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp fpscan $out/bin
 
-    ensureDir $out/opt/f-prot
+    mkdir -p $out/opt/f-prot
     cp fpupdate $out/opt/f-prot
     cp product.data.default $out/opt/f-prot/product.data
     cp license.key $out/opt/f-prot/
@@ -23,12 +23,12 @@ stdenv.mkDerivation rec {
 
     patchelf --interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" $out/opt/f-prot/fpupdate
 
-    ensureDir $out/share/man/
-    ensureDir $out/share/man/man1
+    mkdir -p $out/share/man/
+    mkdir -p $out/share/man/man1
     cp doc/man/fpscan.1 $out/share/man/man1
-    ensureDir $out/share/man/man5
+    mkdir -p $out/share/man/man5
     cp doc/man/f-prot.conf.5 $out/share/man/man5
-    ensureDir $out/share/man/man8
+    mkdir -p $out/share/man/man8
     cp doc/man/fpupdate.8 $out/share/man/man8
   '';
 
diff --git a/pkgs/tools/security/meo/default.nix b/pkgs/tools/security/meo/default.nix
index e18b68c7593f..820919d1a2ef 100644
--- a/pkgs/tools/security/meo/default.nix
+++ b/pkgs/tools/security/meo/default.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp tools/{meo,p11} $out/bin
     cp meo-gui/meo-gui $out/bin
     cp meo-gui/meo-gui $out/bin
diff --git a/pkgs/tools/security/tor/torbrowser.nix b/pkgs/tools/security/tor/torbrowser.nix
index 7be7c79888ea..f220a46bddcf 100644
--- a/pkgs/tools/security/tor/torbrowser.nix
+++ b/pkgs/tools/security/tor/torbrowser.nix
@@ -45,8 +45,8 @@ in stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/share/tor-browser
-    ensureDir $out/bin
+    mkdir -p $out/share/tor-browser
+    mkdir -p $out/bin
     cp -R * $out/share/tor-browser
 
     cat > "$out/bin/tor-browser" << EOF
diff --git a/pkgs/tools/system/storebrowse/default.nix b/pkgs/tools/system/storebrowse/default.nix
index c46372bcd4b6..a997e38ba4a3 100644
--- a/pkgs/tools/system/storebrowse/default.nix
+++ b/pkgs/tools/system/storebrowse/default.nix
@@ -34,7 +34,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp storebrowse $out/bin
   '';
 
diff --git a/pkgs/tools/system/vboot_reference/default.nix b/pkgs/tools/system/vboot_reference/default.nix
index e1c4734bbdaf..087a3212fc2e 100644
--- a/pkgs/tools/system/vboot_reference/default.nix
+++ b/pkgs/tools/system/vboot_reference/default.nix
@@ -31,7 +31,7 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    ensureDir $out/bin
+    mkdir -p $out/bin
     cp build/cgpt/cgpt $out/bin
     cp build/utility/vbutil_kernel $out/bin
     cp build/utility/vbutil_key $out/bin
diff --git a/pkgs/tools/typesetting/tex/pgfplots/default.nix b/pkgs/tools/typesetting/tex/pgfplots/default.nix
index bc47244a5fa8..67739350c6f6 100644
--- a/pkgs/tools/typesetting/tex/pgfplots/default.nix
+++ b/pkgs/tools/typesetting/tex/pgfplots/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation {
   buildPhase = "true";
   
   installPhase = "
-    ensureDir $out/share/texmf-nix
+    mkdir -p $out/share/texmf-nix
     cp -prd * $out/share/texmf-nix
   ";
 }