diff --git a/default.nix b/default.nix
index b81bee1ad65cf3f3ce08b6d1b746e18dfd351247..9d534e1d5662613606799a57a0323373d5b167f4 100644
--- a/default.nix
+++ b/default.nix
@@ -1,11 +1,11 @@
-{ pkgs, args ? {} }:
+{ pkgs, haskellPackages ? pkgs.haskellPackages, args ? {} }:
 
 let
   lib = pkgs.lib;
   haskell = pkgs.haskell;
 
   #rawdrv = pkgs.haskell.packages.ghc921.callCabal2nix "q" ./. args;
-  rawdrv = pkgs.haskellPackages.callCabal2nix "q" ./. args;
+  rawdrv = haskellPackages.callCabal2nix "q" ./. args;
   drv =  haskell.lib.generateOptparseApplicativeCompletions [ "q" ] rawdrv;
 
 in