diff --git a/pkgs/development/libraries/haskell/language-javascript/default.nix b/pkgs/development/libraries/haskell/language-javascript/default.nix
index 68f8006d2a9..17f57fbe546 100644
--- a/pkgs/development/libraries/haskell/language-javascript/default.nix
+++ b/pkgs/development/libraries/haskell/language-javascript/default.nix
@@ -2,8 +2,8 @@
 
 cabal.mkDerivation (self: {
   pname = "language-javascript";
-  version = "0.4.5";
-  sha256 = "0rsggjpxsvaipkibhl90qcj2w2i16g53srbb54v0hajx2msmi0ci";
+  version = "0.4.6";
+  sha256 = "1rqbb44cyvj6iyipi4bzrdd59lk9q1vxh0zvilvc54kqg97y07v6";
   isLibrary = true;
   isExecutable = true;
   buildDepends = [ mtl utf8Light ];
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index d3c90effa23..3ef11809f42 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -910,7 +910,9 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   jsonTypes = callPackage ../development/libraries/haskell/jsonTypes {};
 
-  languageJavascript = callPackage ../development/libraries/haskell/language-javascript {};
+  languageJavascript = callPackage ../development/libraries/haskell/language-javascript {
+    alex = self.alex_3_0_1;
+  };
 
   languageHaskellExtract = callPackage ../development/libraries/haskell/language-haskell-extract {};
 
@@ -1503,7 +1505,7 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
   alex_2_3_3 = callPackage ../development/tools/parsing/alex/2.3.3.nix {};
   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 = self.alex_2_3_1;
+  alex = self.alex_3_0_1;
 
   alexMeta = callPackage ../development/tools/haskell/alex-meta {};