diff --git a/whisper/whisperv6/filter_test.go b/whisper/whisperv6/filter_test.go
index 20dda1680a..42e1f05018 100644
--- a/whisper/whisperv6/filter_test.go
+++ b/whisper/whisperv6/filter_test.go
@@ -844,7 +844,7 @@ func TestTopicsMapping(t *testing.T) {
 		matched := []string{}
 		fs.topicMatcher.matchedTopics(env.Topic, &matched)
 		if !hasFilterID(matched, filterID) {
-			t.Fatalf("failed matchedTopics, step %d.", seed, i)
+			t.Fatalf("failed matchedTopics, step %d.", i)
 		}
 
 		//test match without filter