diff --git a/cmd/plc-mirror/metrics.go b/cmd/plc-mirror/metrics.go
index a5cbdad..2a5cc4a 100644
--- a/cmd/plc-mirror/metrics.go
+++ b/cmd/plc-mirror/metrics.go
@@ -16,6 +16,7 @@ var requestCount = promauto.NewCounterVec(prometheus.CounterOpts{
 }, []string{"status"})
 
 var requestLatency = promauto.NewHistogramVec(prometheus.HistogramOpts{
-	Name: "plcmirror_response_latency_millisecond",
-	Help: "Latency of responses.",
+	Name:    "plcmirror_response_latency_millisecond",
+	Help:    "Latency of responses.",
+	Buckets: prometheus.ExponentialBucketsRange(1, 30000, 20),
 }, []string{"status"})
diff --git a/cmd/plc-mirror/serve.go b/cmd/plc-mirror/serve.go
index ef739a1..bff15ff 100644
--- a/cmd/plc-mirror/serve.go
+++ b/cmd/plc-mirror/serve.go
@@ -67,7 +67,7 @@ func (s *Server) serve(ctx context.Context, req *http.Request) convreq.HttpRespo
 	start := time.Now()
 	updateMetrics := func(c int) {
 		requestCount.WithLabelValues(fmt.Sprint(c)).Inc()
-		requestLatency.WithLabelValues(fmt.Sprint(c)).Observe(float64(time.Now().Sub(start).Milliseconds()))
+		requestLatency.WithLabelValues(fmt.Sprint(c)).Observe(float64(time.Now().Sub(start)) / float64(time.Millisecond))
 	}
 
 	delay := time.Since(s.mirror.LastSuccess())