diff --git a/nix/challenge-bypass-ristretto.nix b/nix/challenge-bypass-ristretto.nix
index e81398666868869f3d872905b54e90b749d10d6b..10bf5e88a11dff116c80776a91f53c8561d166aa 100644
--- a/nix/challenge-bypass-ristretto.nix
+++ b/nix/challenge-bypass-ristretto.nix
@@ -2,8 +2,7 @@
 let
   sources = import ./sources.nix;
 in
-{ fetchFromGitHub
-, callPackage
+{ callPackage
 , libchallenge_bypass_ristretto_ffi_repo ? sources.libchallenge_bypass_ristretto_ffi
 }:
-  import "${libchallenge_bypass_ristretto_ffi_repo}/challenge-bypass-ristretto.nix" { }
+  callPackage "${libchallenge_bypass_ristretto_ffi_repo}/challenge-bypass-ristretto.nix" { }