diff --git a/pkgs/development/haskell-modules/generic-builder.nix b/pkgs/development/haskell-modules/generic-builder.nix
index 0d535b27341d..f8cca65aeb67 100644
--- a/pkgs/development/haskell-modules/generic-builder.nix
+++ b/pkgs/development/haskell-modules/generic-builder.nix
@@ -117,6 +117,8 @@ stdenv.mkDerivation ({
     ${optionalString (versionOlder "7.8" ghc.version && !isLibrary) ''
       configureFlags+=" --ghc-option=-j$NIX_BUILD_CORES"
       setupCompileFlags="-j$NIX_BUILD_CORES"
+    ''}${optionalString stdenv.isDarwin ''
+      configureFlags+=" --with-gcc=$CC"  # Cabal won't find clang without help.
     ''}
 
     packageConfDir="$TMP/package.conf.d"