diff --git a/pkgs/applications/science/logic/sad/default.nix b/pkgs/applications/science/logic/sad/default.nix
index f9b82b5d733..f1066abf693 100644
--- a/pkgs/applications/science/logic/sad/default.nix
+++ b/pkgs/applications/science/logic/sad/default.nix
@@ -8,7 +8,7 @@ stdenv.mkDerivation {
   };
   buildInputs = [ haskell.compiler.ghc844 spass ];
   patches = [
-    ./patch
+    ./patch.patch
     # Since the LTS 12.0 update, <> is an operator in Prelude, colliding with
     # the <> operator with a different meaning defined by this package
     ./monoid.patch
diff --git a/pkgs/applications/science/logic/sad/patch b/pkgs/applications/science/logic/sad/patch.patch
similarity index 100%
rename from pkgs/applications/science/logic/sad/patch
rename to pkgs/applications/science/logic/sad/patch.patch