diff --git a/pkgs/development/libraries/physics/cernlib/default.nix b/pkgs/development/libraries/physics/cernlib/default.nix
index c6a9835d13b6..8c4d688b697e 100644
--- a/pkgs/development/libraries/physics/cernlib/default.nix
+++ b/pkgs/development/libraries/physics/cernlib/default.nix
@@ -16,7 +16,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ gnumake imake makedepend ];
   sourceRoot = ".";
 
-  patches = [ ./patch ];
+  patches = [ ./patch.patch ];
 
   postPatch = ''
     substituteInPlace 2006/src/config/site.def \
diff --git a/pkgs/development/libraries/physics/cernlib/patch b/pkgs/development/libraries/physics/cernlib/patch.patch
similarity index 100%
rename from pkgs/development/libraries/physics/cernlib/patch
rename to pkgs/development/libraries/physics/cernlib/patch.patch