diff --git a/pkgs/development/libraries/haskell/yesod-core/default.nix b/pkgs/development/libraries/haskell/yesod-core/default.nix
index f05477ab8f76..e27f751e6b15 100644
--- a/pkgs/development/libraries/haskell/yesod-core/default.nix
+++ b/pkgs/development/libraries/haskell/yesod-core/default.nix
@@ -13,8 +13,8 @@
 
 cabal.mkDerivation (self: {
   pname = "yesod-core";
-  version = "1.2.20";
-  sha256 = "1gx0xbyx3mydmiwxypzgmpm5ywrxynqyb1myym0mdaxm6dd1v31k";
+  version = "1.2.20.1";
+  sha256 = "188mfw9ag6287azb633xznwrbsavy5k12ycg2aahrxd84g6xjnan";
   buildDepends = [
     aeson attoparsecConduit blazeBuilder blazeHtml blazeMarkup
     caseInsensitive cereal clientsession conduit conduitExtra cookie