diff --git a/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix b/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix
index c2ffa9416c2..2a919789cbb 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-7.6.x.nix
@@ -35,5 +35,9 @@ self: super: {
   transformers = self.transformers_0_4_2_0;
   mtl = self.mtl_2_2_1;
 
+  # https://github.com/haskell/cabal/issues/2322
   Cabal_1_22_0_0 = super.Cabal_1_22_0_0.override { binary = self.binary_0_7_2_3; };
+
+  # https://github.com/tibbe/hashable/issues/85
+  hashable = dontCheck super.hashable;
 }