diff --git a/msgbus.go b/msgbus.go
index 124999d..1e5cee5 100644
--- a/msgbus.go
+++ b/msgbus.go
@@ -600,7 +600,9 @@ func (mb *MessageBus) Subscribe(id, topic string, opts ...SubscribeOption) chan
 				case ch <- msg:
 					n++
 				default:
-					mb.metrics.Counter("bus", "dropped").Inc()
+					if mb.metrics != nil {
+						mb.metrics.Counter("bus", "dropped").Inc()
+					}
 					return ErrBufferFull
 				}
 			}