1 files changed, 4 insertions, 0 deletions
diff --git a/pkgs/development/compilers/ghcjs-ng/8.6/dep-overrides.nix b/pkgs/development/compilers/ghcjs-ng/8.6/dep-overrides.nix
index 53b6dd43134..c54c782fafa 100644
--- a/pkgs/development/compilers/ghcjs-ng/8.6/dep-overrides.nix
+++ b/pkgs/development/compilers/ghcjs-ng/8.6/dep-overrides.nix
@@ -2,6 +2,10 @@
 
 let inherit (haskellLib) doJailbreak dontHaddock;
 in self: super: {
+  ghc-api-ghcjs = super.ghc-api-ghcjs.override
+  {
+    happy = self.happy_1_19_5;
+  };
   haddock-library-ghcjs = doJailbreak super.haddock-library-ghcjs;
   haddock-api-ghcjs = doJailbreak (dontHaddock super.haddock-api-ghcjs);
 }