diff --git a/middleware/metrics/handler.go b/middleware/metrics/handler.go
index 168f0d67a..6d0eb1f84 100644
--- a/middleware/metrics/handler.go
+++ b/middleware/metrics/handler.go
@@ -44,7 +44,7 @@ func Report(state middleware.State, zone, rcode string, size int, start time.Tim
 
 	requestCount.WithLabelValues(zone, net, fam).Inc()
 	requestDuration.WithLabelValues(zone).Observe(float64(time.Since(start) / time.Second))
-	requestSize.WithLabelValues(zone).Observe(float64(state.Size()))
+	requestSize.WithLabelValues(zone, net).Observe(float64(state.Size()))
 	if state.Do() {
 		requestDo.WithLabelValues(zone).Inc()
 	}
diff --git a/middleware/metrics/metrics.go b/middleware/metrics/metrics.go
index 3cbb01614..5c2c37ff8 100644
--- a/middleware/metrics/metrics.go
+++ b/middleware/metrics/metrics.go
@@ -88,7 +88,7 @@ func define() {
 		Name:      "request_size_bytes",
 		Help:      "Size of the EDNS0 UDP buffer in bytes (64K for TCP).",
 		Buckets:   []float64{0, 100, 200, 300, 400, 511, 1023, 2047, 4095, 8291, 16e3, 32e3, 48e3, 64e3},
-	}, []string{"zone"})
+	}, []string{"zone", "proto"})
 
 	requestDo = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: middleware.Namespace,