diff --git a/libraries/GCS_MAVLink/GCS.cpp b/libraries/GCS_MAVLink/GCS.cpp
index 911b8732e2..70439fbfc8 100644
--- a/libraries/GCS_MAVLink/GCS.cpp
+++ b/libraries/GCS_MAVLink/GCS.cpp
@@ -355,7 +355,11 @@ bool GCS::out_of_time() const
 
 void gcs_out_of_space_to_send(mavlink_channel_t chan)
 {
-    gcs().chan(chan)->out_of_space_to_send();
+    GCS_MAVLINK *link = gcs().chan(chan);
+    if (link == nullptr) {
+        return;
+    }
+    link->out_of_space_to_send();
 }
 
 /*