diff --git a/workers.go b/workers.go
index a40c43a..840589f 100644
--- a/workers.go
+++ b/workers.go
@@ -571,6 +571,7 @@ func MQTidyKeepAliveWorker() {
 		t := time.Now()
 		muxClients.Lock()
 		for id, clt := range clients {
+			clt.Mux.Lock()
 			if clt.Active && clt.HeartBeat.Add(3*KeepAliveHeartBeatSeconds*time.Second).Before(time.Now()) {
 				msgs, err := clt.MQ.Channel.QueuePurge(clt.MQ.Queue.Name, false)
 				logOnError(err, "MQTidyKeepAliveWorker : Channel.QueuePurge()")
@@ -592,6 +593,7 @@ func MQTidyKeepAliveWorker() {
 				TGCmdQueue <- cmd
 				clt.Active = false
 			}
+			clt.Mux.Unlock()
 		}
 		muxClients.Unlock()
 		time.Sleep(time.Until(t.Add(time.Second)))