1 files changed, 3 insertions, 1 deletions
diff --git a/pkgs/development/tools/haskell/BNFC/default.nix b/pkgs/development/tools/haskell/BNFC/default.nix
index c6cbc4a53587..3cb85b86acbd 100644
--- a/pkgs/development/tools/haskell/BNFC/default.nix
+++ b/pkgs/development/tools/haskell/BNFC/default.nix
@@ -1,4 +1,4 @@
-{ cabal, mtl }:
+{ cabal, mtl, fetchurl }:
 
 cabal.mkDerivation (self: {
   pname = "BNFC";
@@ -7,6 +7,8 @@ cabal.mkDerivation (self: {
   isLibrary = true;
   isExecutable = true;
   buildDepends = [ mtl ];
+  patches = [ (fetchurl { url = "https://github.com/BNFC/bnfc/pull/3.patch"; sha256 = "103l04ylzswgxrmpv5zy6dd0jyr96z21mdkpgk1z4prvn8wjl624"; }) ];
+  patchFlags = "-p2";
   meta = {
     homepage = "http://bnfc.digitalgrammars.com/";
     description = "A compiler front-end generator";