diff --git a/tests/functional/config.nix.in b/tests/functional/config.nix.in
index 70b4d53fe..dd4b70f49 100644
--- a/tests/functional/config.nix.in
+++ b/tests/functional/config.nix.in
@@ -24,7 +24,7 @@ rec {
 
   mkDerivation = args:
     derivation ({
-      inherit system;
+      inherit system shell;
       builder = shell;
       args = ["-e" args.builder or (builtins.toFile "builder-${args.name}.sh" ''
         if [ -e "$NIX_ATTRS_SH_FILE" ]; then source $NIX_ATTRS_SH_FILE; fi;