diff --git a/tests/fixed.nix.in b/tests/fixed.nix.in
index 47eff91e05..c7dd99e6f2 100644
--- a/tests/fixed.nix.in
+++ b/tests/fixed.nix.in
@@ -41,8 +41,8 @@ rec {
   # Test for building two derivations in parallel that produce the
   # same output path because they're fixed-output derivations.
   parallelSame = [
-    (f2 "foo" ./fixed.builder2.sh "flat" "md5" "3670af73070fa14077ad74e0f5ea4e42")
-    (f2 "bar" ./fixed.builder2.sh "flat" "md5" "3670af73070fa14077ad74e0f5ea4e42")
+    (f2 "foo" ./fixed.builder2.sh "recursive" "md5" "3670af73070fa14077ad74e0f5ea4e42")
+    (f2 "bar" ./fixed.builder2.sh "recursive" "md5" "3670af73070fa14077ad74e0f5ea4e42")
   ];
 
-}
\ No newline at end of file
+}