diff --git a/pkgs/development/tools/parsing/alex/3.0.4.nix b/pkgs/development/tools/parsing/alex/3.0.5.nix
similarity index 81%
rename from pkgs/development/tools/parsing/alex/3.0.4.nix
rename to pkgs/development/tools/parsing/alex/3.0.5.nix
index 3160570b240d..683ada1bf022 100644
--- a/pkgs/development/tools/parsing/alex/3.0.4.nix
+++ b/pkgs/development/tools/parsing/alex/3.0.5.nix
@@ -2,13 +2,12 @@
 
 cabal.mkDerivation (self: {
   pname = "alex";
-  version = "3.0.4";
-  sha256 = "0fgh7ziwxyb140wghh7dpndh41sixcssnba0q942cvkg77m6ah6d";
+  version = "3.0.5";
+  sha256 = "0ncnp7cl7dlfcrwzzcp8j59i9j5r66wim1yib9g3b3jkl0bn8cn3";
   isLibrary = false;
   isExecutable = true;
   buildDepends = [ QuickCheck ];
   buildTools = [ perl ];
-  doCheck = false;
   meta = {
     homepage = "http://www.haskell.org/alex/";
     description = "Alex is a tool for generating lexical analysers in Haskell";
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index 8275aee4f52c..d1a0262bc1c8 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -159,7 +159,7 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
     xhtml        = self.xhtml_3000_2_1;         # 7.6 ok
     zlib         = self.zlib_0_5_4_1;           # 7.6 ok
     cabalInstall = self.cabalInstall_1_16_0_2;  # 7.6 ok
-    alex         = self.alex_3_0_4;             # 7.6 ok
+    alex         = self.alex_3_0_5;             # 7.6 ok
     haddock      = self.haddock_2_13_1;         # 7.6 ok
     happy        = self.happy_1_18_10;          # 7.6 ok
     primitive    = self.primitive_0_5_0_1; # semi-official, but specified
@@ -2013,8 +2013,8 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
   alex_2_3_5 = callPackage ../development/tools/parsing/alex/2.3.5.nix {};
   alex_3_0_1 = callPackage ../development/tools/parsing/alex/3.0.1.nix {};
   alex_3_0_2 = callPackage ../development/tools/parsing/alex/3.0.2.nix {};
-  alex_3_0_4 = callPackage ../development/tools/parsing/alex/3.0.4.nix {};
-  alex = self.alex_3_0_4;
+  alex_3_0_5 = callPackage ../development/tools/parsing/alex/3.0.5.nix {};
+  alex = self.alex_3_0_5;
 
   alexMeta = callPackage ../development/tools/haskell/alex-meta {};