diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index b8a5284f5b..7c0e654823 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -2053,6 +2053,8 @@ void GCS_MAVLINK::service_statustext(void)
 {
     GCS::StatusTextQueue &_statustext_queue = gcs().statustext_queue();
 
+    WITH_SEMAPHORE(comm_chan_lock(chan));
+
     const uint8_t chan_bit = (1U<<chan);
     // note the lack of idx++ here.  We may remove the iteration item
     // from the queue as the last thing we do, in which case we don't