diff --git a/metrics/prometheus/collector.go b/metrics/prometheus/collector.go
index 25c7b4f4c4..ea85abc1b2 100644
--- a/metrics/prometheus/collector.go
+++ b/metrics/prometheus/collector.go
@@ -126,5 +126,7 @@ func (c *collector) writeSummaryPercentile(name, p string, value interface{}) {
 }
 
 func mutateKey(key string) string {
-	return strings.Replace(key, "/", "_", -1)
+	key = strings.Replace(key, "/", "_", -1)
+	key = strings.Replace(key, "-", "_", -1)
+	return key
 }