diff --git a/pkgs/gf-core/default.nix b/pkgs/gf-core/default.nix
index cc27041..421f235 100644
--- a/pkgs/gf-core/default.nix
+++ b/pkgs/gf-core/default.nix
@@ -1,9 +1,9 @@
 { haskell
-, haskellPackages
 , stdenv
 , fetchFromGitHub
 , gf-pgf
 , applyPatches
+, compiler ? "ghc98"
 }:
 
 let
@@ -21,7 +21,8 @@ let
       ./fix-cabal-syntax-error.patch
     ];
   };
-  pkg = haskellPackages.callCabal2nixWithOptions "gf" src "--flag=-server" {};
+  hpkgs = haskell.packages.${compiler};
+  pkg = hpkgs.callCabal2nixWithOptions "gf" src "--flag=-server" {};
 in haskell.lib.overrideCabal pkg (prev: {
   jailbreak = true;
   configureFlags = [ "-f" "c-runtime" ];