diff --git a/pkgs/development/libraries/haskell/classy-prelude/default.nix b/pkgs/development/libraries/haskell/classy-prelude/default.nix
index 8c5a94d4d12..dbc53987861 100644
--- a/pkgs/development/libraries/haskell/classy-prelude/default.nix
+++ b/pkgs/development/libraries/haskell/classy-prelude/default.nix
@@ -4,8 +4,8 @@
 
 cabal.mkDerivation (self: {
   pname = "classy-prelude";
-  version = "0.4.1";
-  sha256 = "14s1qirss8qbicdw4bc7smdnk1xrpp1xsii8kgmrb1z4ji0h9bf1";
+  version = "0.4.2";
+  sha256 = "082zqhyswzlnl250g8pf88nmh7pkwxwjwnkp0pm9960qsl6kbn7s";
   buildDepends = [
     basicPrelude hashable systemFilepath text transformers
     unorderedContainers vector