diff --git a/lib/attrsets.nix b/lib/attrsets.nix
index 7c93d8698de0..f314c02ff32b 100644
--- a/lib/attrsets.nix
+++ b/lib/attrsets.nix
@@ -1,7 +1,7 @@
 # Operations on attribute sets.
 
 with {
-  inherit (builtins) head tail isString;
+  inherit (builtins) head tail;
   inherit (import ./trivial.nix) or;
   inherit (import ./default.nix) fold;
   inherit (import ./strings.nix) concatStringsSep;
@@ -100,7 +100,7 @@ rec {
          (AttrSet -> Bool) -> AttrSet -> AttrSet
 
      Example:
-       collect builtins.isList { a = { b = ["b"]; }; c = [1]; }
+       collect isList { a = { b = ["b"]; }; c = [1]; }
        => [["b"] [1]]
 
        collect (x: x ? outPath)
diff --git a/lib/default.nix b/lib/default.nix
index fc92e04503b2..4b6027c437be 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -21,8 +21,6 @@ let
 in
   { inherit trivial lists strings stringsWithDeps attrsets sources options
       modules types meta debug maintainers licenses platforms systems;
-    # Pull in some builtins not included elsewhere.
-    inherit (builtins) pathExists readFile;
   }
   # !!! don't include everything at top-level; perhaps only the most
   # commonly used functions.
diff --git a/lib/lists.nix b/lib/lists.nix
index d0b09539bf69..2a1fa7205637 100644
--- a/lib/lists.nix
+++ b/lib/lists.nix
@@ -1,14 +1,16 @@
 # General list operations.
-let
 
-  inherit (import ./trivial.nix) deepSeq;
+with import ./trivial.nix;
+
+let
 
   inc = builtins.add 1;
 
   dec = n: builtins.sub n 1;
 
 in rec {
-  inherit (builtins) head tail length isList add sub lessThan elemAt;
+
+  inherit (builtins) head tail length isList elemAt;
 
 
   # Create a list consisting of a single element.  `singleton x' is
@@ -55,7 +57,7 @@ in rec {
           else [ (f (inc n) (elemAt list n)) ] ++ imap' (inc n);
     in imap' 0;
 
-    
+
   # Concatenate a list of lists.
   concatLists = builtins.concatLists or (fold (x: y: x ++ y) []);
 
@@ -72,7 +74,7 @@ in rec {
     then fold (x: y: (flatten x) ++ y) [] x
     else [x];
 
-    
+
   # Filter a list using a predicate; that is, return a list containing
   # every element from `list' for which `pred' returns true.
   filter =
@@ -80,11 +82,11 @@ in rec {
     (pred: list:
       fold (x: y: if pred x then [x] ++ y else y) [] list);
 
-    
+
   # Remove elements equal to 'e' from a list.  Useful for buildInputs.
   remove = e: filter (x: x != e);
 
-  
+
   # Return true if `list' has an element `x'.
   elem =
     builtins.elem or
@@ -106,7 +108,7 @@ in rec {
   findFirst = pred: default: list:
     let found = filter pred list;
     in if found == [] then default else head found;
-       
+
 
   # Return true iff function `pred' returns true for at least element
   # of `list'.
@@ -136,16 +138,16 @@ in rec {
   # If argument is a list, return it; else, wrap it in a singleton
   # list.  If you're using this, you should almost certainly
   # reconsider if there isn't a more "well-typed" approach.
-  toList = x: if builtins.isList x then x else [x];
+  toList = x: if isList x then x else [x];
+
 
-    
   # Return a list of integers from `first' up to and including `last'.
   range = first: last:
-    if builtins.lessThan last first
+    if lessThan last first
     then []
-    else [first] ++ range (builtins.add first 1) last;
+    else [first] ++ range (add first 1) last;
+
 
-    
   # Partition the elements of a list in two lists, `right' and
   # `wrong', depending on the evaluation of a predicate.
   partition = pred:
@@ -160,7 +162,7 @@ in rec {
     let
       len1 = length fst;
       len2 = length snd;
-      len = if builtins.lessThan len1 len2 then len1 else len2;
+      len = if lessThan len1 len2 then len1 else len2;
       zipListsWith' = n:
         if n != len then
           [ (f (elemAt fst n) (elemAt snd n)) ]
@@ -207,7 +209,7 @@ in rec {
           [ (elemAt list n) ] ++ take' (inc n);
     in take' 0;
 
-    
+
   # Remove the first (at most) N elements of a list.
   drop = count: list:
     let
@@ -219,7 +221,8 @@ in rec {
           drop' (dec n) ++ [ (elemAt list n) ];
     in drop' (dec len);
 
-    
+
+  # Return the last element of a list.
   last = list:
     assert list != []; elemAt list (dec (length list));
 
@@ -237,5 +240,7 @@ in rec {
         else [];
     in zipTwoLists' 0;
 
+
   deepSeqList = xs: y: if any (x: deepSeq x false) xs then y else y;
+
 }
diff --git a/lib/modules.nix b/lib/modules.nix
index 071809daa58e..fa31ce6399ce 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -42,7 +42,7 @@ rec {
   closeModules = modules: args:
     let
       toClosureList = file: parentKey: imap (n: x:
-        if isAttrs x || builtins.isFunction x then
+        if isAttrs x || isFunction x then
           unifyModuleSyntax file "${parentKey}:anon-${toString n}" (applyIfFunction x args)
         else
           unifyModuleSyntax (toString x) (toString x) (applyIfFunction (import x) args));
@@ -74,7 +74,7 @@ rec {
         config = removeAttrs m ["key" "_file" "require" "imports"];
       };
 
-  applyIfFunction = f: arg: if builtins.isFunction f then f arg else f;
+  applyIfFunction = f: arg: if isFunction f then f arg else f;
 
   /* Merge a list of modules.  This will recurse over the option
      declarations in all modules, combining them into a single set.
@@ -260,7 +260,7 @@ rec {
       options' = opt.options or
         (throw "Option `${showOption loc'}' has type optionSet but has no option attribute.");
       coerce = x:
-        if builtins.isFunction x then x
+        if isFunction x then x
         else { config, ... }: { options = x; };
       options = map coerce (flatten options');
       f = tp:
diff --git a/lib/options.nix b/lib/options.nix
index 63798c4faa3b..71e02db58f69 100644
--- a/lib/options.nix
+++ b/lib/options.nix
@@ -34,12 +34,12 @@ rec {
   mergeDefaultOption = loc: defs:
     let list = getValues defs; in
     if length list == 1 then head list
-    else if all builtins.isFunction list then x: mergeDefaultOption loc (map (f: f x) list)
+    else if all isFunction list then x: mergeDefaultOption loc (map (f: f x) list)
     else if all isList list then concatLists list
     else if all isAttrs list then fold lib.mergeAttrs {} list
-    else if all builtins.isBool list then fold lib.or false list
-    else if all builtins.isString list then lib.concatStrings list
-    else if all builtins.isInt list && all (x: x == head list) list then head list
+    else if all isBool list then fold lib.or false list
+    else if all isString list then lib.concatStrings list
+    else if all isInt list && all (x: x == head list) list then head list
     else throw "Cannot merge definitions of `${showOption loc}' given in ${showFiles (getFiles defs)}.";
 
   /* Obsolete, will remove soon.  Specify an option type or apply
@@ -54,7 +54,7 @@ rec {
 
   mergeListOption = mergeTypedOption "list" isList concatLists;
 
-  mergeStringOption = mergeTypedOption "string" builtins.isString lib.concatStrings;
+  mergeStringOption = mergeTypedOption "string" isString lib.concatStrings;
 
   mergeOneOption = loc: defs:
     if defs == [] then abort "This case should never happen."
diff --git a/lib/strings.nix b/lib/strings.nix
index 024a9ac7d7a2..cd748f02cc63 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -7,7 +7,8 @@ inherit (builtins) add sub lessThan length;
 in
 
 rec {
-  inherit (builtins) stringLength substring head tail;
+
+  inherit (builtins) stringLength substring head tail isString;
 
 
   # Concatenate a list of strings.
diff --git a/lib/trivial.nix b/lib/trivial.nix
index 8af3474f2a67..760a74ce6664 100644
--- a/lib/trivial.nix
+++ b/lib/trivial.nix
@@ -16,7 +16,7 @@ rec {
   or = x: y: x || y;
   and = x: y: x && y;
   mergeAttrs = x: y: x // y;
-  
+
   # Take a function and evaluate it with its own returned value.
   fix = f: let result = f result; in result;
 
@@ -26,7 +26,7 @@ rec {
   # `seq x y' evaluates x, then returns y.  That is, it forces strict
   # evaluation of its first argument.
   seq = x: y: if x == null then y else y;
-  
+
   # Like `seq', but recurses into lists and attribute sets to force evaluation
   # of all list elements/attributes.
   deepSeq = x: y:
@@ -35,4 +35,10 @@ rec {
     else if builtins.isAttrs x
       then deepSeqAttrs x y
       else seq x y;
+
+  # Pull in some builtins not included elsewhere.
+  inherit (builtins)
+    pathExists readFile isBool isFunction
+    isInt add sub lessThan;
+
 }
diff --git a/lib/types.nix b/lib/types.nix
index 09b29a762e1d..bdd21f123952 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -48,19 +48,19 @@ rec {
 
     bool = mkOptionType {
       name = "boolean";
-      check = builtins.isBool;
+      check = isBool;
       merge = loc: fold (x: y: x.value || y) false;
     };
 
     int = mkOptionType {
       name = "integer";
-      check = builtins.isInt;
+      check = isInt;
       merge = mergeOneOption;
     };
 
     str = mkOptionType {
       name = "string";
-      check = builtins.isString;
+      check = isString;
       merge = mergeOneOption;
     };
 
@@ -68,7 +68,7 @@ rec {
     # separator between the values).
     separatedString = sep: mkOptionType {
       name = "string";
-      check = builtins.isString;
+      check = isString;
       merge = loc: defs: concatStringsSep sep (getValues defs);
     };
 
@@ -170,7 +170,7 @@ rec {
 
     functionTo = elemType: mkOptionType {
       name = "function that evaluates to a(n) ${elemType.name}";
-      check = builtins.isFunction;
+      check = isFunction;
       merge = loc: defs:
         fnArgs: elemType.merge loc (map (fn: { inherit (fn) file; value = fn.value fnArgs; }) defs);
       getSubOptions = elemType.getSubOptions;
@@ -183,10 +183,10 @@ rec {
       in
       mkOptionType rec {
         name = "submodule";
-        check = x: isAttrs x || builtins.isFunction x;
+        check = x: isAttrs x || isFunction x;
         merge = loc: defs:
           let
-            coerce = def: if builtins.isFunction def then def else { config = def; };
+            coerce = def: if isFunction def then def else { config = def; };
             modules = opts' ++ map (def: { _file = def.file; imports = [(coerce def.value)]; }) defs;
           in (evalModules { inherit modules; args.name = last loc; prefix = loc; }).config;
         getSubOptions = prefix: (evalModules
diff --git a/nixos/modules/config/shells-environment.nix b/nixos/modules/config/shells-environment.nix
index e3fbdd7aaec1..0b4f75a35216 100644
--- a/nixos/modules/config/shells-environment.nix
+++ b/nixos/modules/config/shells-environment.nix
@@ -31,9 +31,9 @@ in
             res = (head defs').value;
           in
           if isList res then concatLists (getValues defs')
-          else if builtins.lessThan 1 (length defs') then
+          else if lessThan 1 (length defs') then
             throw "The option `${showOption loc}' is defined multiple times, in ${showFiles (getFiles defs)}."
-          else if !builtins.isString res then
+          else if !isString res then
             throw "The option `${showOption loc}' does not have a string value, in ${showFiles (getFiles defs)}."
           else res;
       });
diff --git a/nixos/modules/config/sysctl.nix b/nixos/modules/config/sysctl.nix
index 31441bad6157..f987c9c9e944 100644
--- a/nixos/modules/config/sysctl.nix
+++ b/nixos/modules/config/sysctl.nix
@@ -6,7 +6,7 @@ let
 
   sysctlOption = mkOptionType {
     name = "sysctl option value";
-    check = x: builtins.isBool x || builtins.isString x || builtins.isInt x;
+    check = x: isBool x || isString x || isInt x;
     merge = args: defs: (last defs).value; # FIXME: hacky way to allow overriding in configuration.nix.
   };
 
diff --git a/nixos/modules/hardware/network/b43.nix b/nixos/modules/hardware/network/b43.nix
index 8f45bd4d3f1a..03f81f92ef0b 100644
--- a/nixos/modules/hardware/network/b43.nix
+++ b/nixos/modules/hardware/network/b43.nix
@@ -1,4 +1,6 @@
-{pkgs, config, ...}:
+{ config, pkgs, ... }:
+
+with pkgs.lib;
 
 let kernelVersion = config.boot.kernelPackages.kernel.version; in
 
@@ -8,9 +10,9 @@ let kernelVersion = config.boot.kernelPackages.kernel.version; in
 
   options = {
 
-    networking.enableB43Firmware = pkgs.lib.mkOption {
+    networking.enableB43Firmware = mkOption {
       default = false;
-      type = pkgs.lib.types.bool;
+      type = types.bool;
       description = ''
         Turn on this option if you want firmware for the NICs supported by the b43 module.
       '';
@@ -21,11 +23,11 @@ let kernelVersion = config.boot.kernelPackages.kernel.version; in
 
   ###### implementation
 
-  config = pkgs.lib.mkIf config.networking.enableB43Firmware {
-    assertions = [ {
-      assertion = builtins.lessThan 0 (builtins.compareVersions kernelVersion "3.2");
-      message = "b43 firmware for kernels older than 3.2 not packaged yet!";
-    } ];
+  config = mkIf config.networking.enableB43Firmware {
+    assertions = singleton
+      { assertion = lessThan 0 (builtins.compareVersions kernelVersion "3.2");
+        message = "b43 firmware for kernels older than 3.2 not packaged yet!";
+      };
     hardware.firmware = [ pkgs.b43Firmware_5_1_138 ];
   };
 
diff --git a/nixos/modules/installer/cd-dvd/channel.nix b/nixos/modules/installer/cd-dvd/channel.nix
index bcf3dbb3f735..9aca5b89d258 100644
--- a/nixos/modules/installer/cd-dvd/channel.nix
+++ b/nixos/modules/installer/cd-dvd/channel.nix
@@ -11,7 +11,7 @@ let
   # CD.  These are installed into the "nixos" channel of the root
   # user, as expected by nixos-rebuild/nixos-install.
   channelSources = pkgs.runCommand "nixos-${config.system.nixosVersion}"
-    { expr = builtins.readFile ../../../lib/channel-expr.nix; }
+    { expr = readFile ../../../lib/channel-expr.nix; }
     ''
       mkdir -p $out/nixos
       cp -prd ${pkgs.path} $out/nixos/nixpkgs
diff --git a/nixos/modules/services/misc/disnix.nix b/nixos/modules/services/misc/disnix.nix
index 72b98d1f84a5..82526b154e7a 100644
--- a/nixos/modules/services/misc/disnix.nix
+++ b/nixos/modules/services/misc/disnix.nix
@@ -111,7 +111,7 @@ in
         // optionalAttrs (config.services.tomcat.enable) { tomcatPort = 8080; }
         // optionalAttrs (config.services.svnserve.enable) { svnBaseDir = config.services.svnserve.svnBaseDir; }
         // optionalAttrs (cfg.publishInfrastructure.enableAuthentication) (
-          optionalAttrs (config.services.mysql.enable) { mysqlUsername = "root"; mysqlPassword = builtins.readFile config.services.mysql.rootPassword; })
+          optionalAttrs (config.services.mysql.enable) { mysqlUsername = "root"; mysqlPassword = readFile config.services.mysql.rootPassword; })
         )
     ;
 
@@ -152,7 +152,7 @@ in
               ${concatMapStrings (infrastructureAttrName:
                 let infrastructureAttrValue = getAttr infrastructureAttrName (cfg.infrastructure);
                 in
-                if builtins.isInt infrastructureAttrValue then
+                if isInt infrastructureAttrValue then
                 ''${infrastructureAttrName}=${toString infrastructureAttrValue} \
                 ''
                 else
diff --git a/nixos/modules/services/networking/ssh/sshd.nix b/nixos/modules/services/networking/ssh/sshd.nix
index 7a2335847e3a..85b6ab1efecf 100644
--- a/nixos/modules/services/networking/ssh/sshd.nix
+++ b/nixos/modules/services/networking/ssh/sshd.nix
@@ -19,7 +19,7 @@ let
 
   knownHostsFile = pkgs.writeText "ssh_known_hosts" (
     flip concatMapStrings knownHosts (h:
-      "${concatStringsSep "," h.hostNames} ${builtins.readFile h.publicKeyFile}"
+      "${concatStringsSep "," h.hostNames} ${readFile h.publicKeyFile}"
     )
   );
 
@@ -59,7 +59,7 @@ let
       mode = "0444";
       source = pkgs.writeText "${u.name}-authorized_keys" ''
         ${concatStringsSep "\n" u.openssh.authorizedKeys.keys}
-        ${concatMapStrings (f: builtins.readFile f + "\n") u.openssh.authorizedKeys.keyFiles}
+        ${concatMapStrings (f: readFile f + "\n") u.openssh.authorizedKeys.keyFiles}
       '';
     };
     usersWithKeys = attrValues (flip filterAttrs config.users.extraUsers (n: u:
diff --git a/nixos/modules/services/torrent/transmission.nix b/nixos/modules/services/torrent/transmission.nix
index 063332d48628..68f9b0647c0e 100644
--- a/nixos/modules/services/torrent/transmission.nix
+++ b/nixos/modules/services/torrent/transmission.nix
@@ -15,7 +15,7 @@ let
   toOption = x:
     if x == true then "true"
     else if x == false then "false"
-    else if builtins.isInt x then toString x
+    else if isInt x then toString x
     else toString ''\"${x}\"'';
 
   # All lines in settings.json end with a ',' (comma), except for the last
diff --git a/nixos/modules/services/web-servers/apache-httpd/default.nix b/nixos/modules/services/web-servers/apache-httpd/default.nix
index d21b6da0e772..900948893489 100644
--- a/nixos/modules/services/web-servers/apache-httpd/default.nix
+++ b/nixos/modules/services/web-servers/apache-httpd/default.nix
@@ -17,8 +17,8 @@ let
   getPort = cfg: if cfg.port != 0 then cfg.port else if cfg.enableSSL then 443 else 80;
 
   extraModules = attrByPath ["extraModules"] [] mainCfg;
-  extraForeignModules = filter builtins.isAttrs extraModules;
-  extraApacheModules = filter (x: !(builtins.isAttrs x)) extraModules; # I'd prefer using builtins.isString here, but doesn't exist yet
+  extraForeignModules = filter isAttrs extraModules;
+  extraApacheModules = filter isString extraModules;
 
 
   makeServerInfo = cfg: {
diff --git a/nixos/modules/system/activation/activation-script.nix b/nixos/modules/system/activation/activation-script.nix
index e012c977164e..1545bcb8a1f9 100644
--- a/nixos/modules/system/activation/activation-script.nix
+++ b/nixos/modules/system/activation/activation-script.nix
@@ -71,7 +71,7 @@ in
 
             ${
               let
-                set' = mapAttrs (n: v: if builtins.isString v then noDepEntry v else v) set;
+                set' = mapAttrs (n: v: if isString v then noDepEntry v else v) set;
                 withHeadlines = addAttributeName set';
               in textClosureMap id (withHeadlines) (attrNames withHeadlines)
             }