diff --git a/pkgs/development/libraries/haskell/bytestring-lexing/default.nix b/pkgs/development/libraries/haskell/bytestring-lexing/default.nix
index 2de7eec8eb5..77bf20f3d81 100644
--- a/pkgs/development/libraries/haskell/bytestring-lexing/default.nix
+++ b/pkgs/development/libraries/haskell/bytestring-lexing/default.nix
@@ -2,8 +2,8 @@
 
 cabal.mkDerivation (self: {
   pname = "bytestring-lexing";
-  version = "0.4.0";
-  sha256 = "1lww38rab9k8drndqkg306kiq6663i89sq6l1bvjv6cs13acc8wr";
+  version = "0.4.2";
+  sha256 = "0s9rip1ik7f29n2i88277vhy7dqhc2bb5bb9l6fd47disb78ic9h";
   buildTools = [ alex ];
   meta = {
     homepage = "http://code.haskell.org/~wren/";