diff --git a/plugins/inputs/kafka_consumer/kafka_consumer.go b/plugins/inputs/kafka_consumer/kafka_consumer.go
index 2703bb52d..997988ca6 100644
--- a/plugins/inputs/kafka_consumer/kafka_consumer.go
+++ b/plugins/inputs/kafka_consumer/kafka_consumer.go
@@ -360,8 +360,8 @@ func (h *ConsumerGroupHandler) Handle(session sarama.ConsumerGroupSession, msg *
 		}
 	}
 
-	id := h.acc.AddTrackingMetricGroup(metrics)
 	h.mu.Lock()
+	id := h.acc.AddTrackingMetricGroup(metrics)
 	h.undelivered[id] = Message{session: session, message: msg}
 	h.mu.Unlock()
 	return nil