diff --git a/pkgs/development/interpreters/maude/default.nix b/pkgs/development/interpreters/maude/default.nix
index 9ead7176d4ed..30013946886b 100644
--- a/pkgs/development/interpreters/maude/default.nix
+++ b/pkgs/development/interpreters/maude/default.nix
@@ -46,6 +46,11 @@ stdenv.mkDerivation rec {
     install -D -m 444 full-maude.maude $out/share/maude/full-maude.maude
   '';
 
+  # bison -dv surface.yy -o surface.c
+  # mv surface.c surface.cc
+  # mv: cannot stat 'surface.c': No such file or directory
+  enableParallelBuilding = false;
+
   meta = {
     homepage = http://maude.cs.illinois.edu/;
     description = "High-level specification language";
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index f857cc0183df..d8477449e2ff 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1182,9 +1182,7 @@ with pkgs;
 
   clipster = callPackage ../tools/misc/clipster { };
 
-  coprthr = callPackage ../development/libraries/coprthr {
-    flex = flex_2_5_35;
-  };
+  coprthr = callPackage ../development/libraries/coprthr { };
 
   cplex = callPackage ../applications/science/math/cplex { releasePath = config.cplex.releasePath or null; };
 
@@ -7721,10 +7719,7 @@ with pkgs;
 
   lush2 = callPackage ../development/interpreters/lush {};
 
-  maude = callPackage ../development/interpreters/maude {
-    bison = bison2;
-    flex = flex_2_5_35;
-  };
+  maude = callPackage ../development/interpreters/maude { };
 
   mesos = callPackage ../applications/networking/cluster/mesos {
     sasl = cyrus_sasl;
@@ -14184,9 +14179,7 @@ with pkgs;
 
   gpu-switch = callPackage ../os-specific/linux/gpu-switch { };
 
-  gradm = callPackage ../os-specific/linux/gradm {
-    flex = flex_2_5_35;
-  };
+  gradm = callPackage ../os-specific/linux/gradm { };
 
   hd-idle = callPackage ../os-specific/linux/hd-idle { };
 
@@ -21766,9 +21759,7 @@ with pkgs;
 
   scilab-bin = callPackage ../applications/science/math/scilab-bin {};
 
-  scotch = callPackage ../applications/science/math/scotch {
-    flex = flex_2_5_35;
-  };
+  scotch = callPackage ../applications/science/math/scotch { };
 
   msieve = callPackage ../applications/science/math/msieve { };