diff --git a/prog/weavedns/main.go b/prog/weavedns/main.go
index e915905c..f22ef8e5 100644
--- a/prog/weavedns/main.go
+++ b/prog/weavedns/main.go
@@ -55,7 +55,7 @@ func main() {
 	flag.BoolVar(&watch, "watch", true, "watch the docker socket for container events")
 	flag.BoolVar(&debug, "debug", false, "output debugging info to stderr")
 	// advanced options
-	flag.IntVar(&negTTL, "neg-ttl", 0, "negative TTL (in secs) for unanswered queries for local names")
+	flag.IntVar(&negTTL, "neg-ttl", 0, "negative TTL (in secs) for unanswered queries for local names (0=same value as -ttl")
 	flag.IntVar(&refreshInterval, "refresh", weavedns.DefaultRefreshInterval, "refresh interval (in secs) for local names (0=disable)")
 	flag.IntVar(&maxAnswers, "max-answers", weavedns.DefaultMaxAnswers, "maximum number of answers returned to clients (0=unlimited)")
 	flag.IntVar(&relevantTime, "relevant", weavedns.DefaultRelevantTime, "life time for info in the absence of queries (in secs)")