diff --git a/pkgs/test/stdenv/default.nix b/pkgs/test/stdenv/default.nix
index bad6eb7ba7aa..c7bb07f625ed 100644
--- a/pkgs/test/stdenv/default.nix
+++ b/pkgs/test/stdenv/default.nix
@@ -113,7 +113,7 @@ in
 
     # Assumption: the first output* variable to be configured is
     #   _overrideFirst outputDev "dev" "out"
-    expectedMsg = "_assignFirst: could not find a non-empty variable to assign to outputDev. The following variables were all unset or empty: dev out.";
+    expectedMsg = "error: _assignFirst: could not find a non-empty variable to assign to outputDev.\n       The following variables were all unset or empty:\n           dev out";
   } ''
     grep -F "$expectedMsg" $result/testBuildFailure.log >/dev/null
     touch $out