diff --git a/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix b/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix
index 5257717673a..5d84dca47e8 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix
@@ -128,4 +128,7 @@ self: super: {
   # Fix evaluation in GHC >=7.8: https://github.com/lambdabot/lambdabot/issues/116
   lambdabot = appendPatch super.lambdabot ./lambdabot-fix-ghc78.patch;
 
+  # Needs hashable on pre 7.10.x compilers.
+  nats = addBuildDepend super.nats self.hashable;
+
 }