diff --git a/lib/internal/test_runner/tests_stream.js b/lib/internal/test_runner/tests_stream.js
index ecbc407e01f318..2ae1ce923982ea 100644
--- a/lib/internal/test_runner/tests_stream.js
+++ b/lib/internal/test_runner/tests_stream.js
@@ -114,11 +114,12 @@ class TestsStream extends Readable {
     });
   }
 
-  diagnostic(nesting, loc, message) {
+  diagnostic(nesting, loc, message, level = 'info') {
     this[kEmitMessage]('test:diagnostic', {
       __proto__: null,
       nesting,
       message,
+      level,
       ...loc,
     });
   }