diff --git a/lib/mqtt.c b/lib/mqtt.c
index f077e6c3dc..fcd40b41e6 100644
--- a/lib/mqtt.c
+++ b/lib/mqtt.c
@@ -128,6 +128,10 @@ static CURLcode mqtt_send(struct Curl_easy *data,
     mq->sendleftovers = sendleftovers;
     mq->nsend = nsend;
   }
+  else {
+    mq->sendleftovers = NULL;
+    mq->nsend = 0;
+  }
   return result;
 }