diff --git a/pkgs/top-level/guile-2-test.nix b/pkgs/top-level/guile-2-test.nix
index 24cf313ba73..bb2b7daa83f 100644
--- a/pkgs/top-level/guile-2-test.nix
+++ b/pkgs/top-level/guile-2-test.nix
@@ -7,7 +7,9 @@ let
   allPackages = import ./all-packages.nix;
 
   pkgs = allPackages {
-    packageOverrides = pkgs: pkgs // { guile = pkgs.guile_1_9; };
+    config = {
+      packageOverrides = pkgs: pkgs // { guile = pkgs.guile_1_9; };
+    };
   };
 
   inherit (pkgs.lib.platforms) linux darwin cygwin allBut all;