diff --git a/libraries/AP_GPS/AP_GPS.cpp b/libraries/AP_GPS/AP_GPS.cpp
index c2af85c496..7710290368 100644
--- a/libraries/AP_GPS/AP_GPS.cpp
+++ b/libraries/AP_GPS/AP_GPS.cpp
@@ -20,6 +20,7 @@
 #include <AP_Notify/AP_Notify.h>
 #include <GCS_MAVLink/GCS.h>
 #include <AP_BoardConfig/AP_BoardConfig.h>
+#include <climits>
 
 #include "AP_GPS_NOVA.h"
 #include "AP_GPS_ERB.h"
@@ -258,6 +259,9 @@ const AP_Param::GroupInfo AP_GPS::var_info[] = {
 // constructor
 AP_GPS::AP_GPS()
 {
+    static_assert((sizeof(_initialisation_blob) * (CHAR_BIT + 2)) < (4800 * GPS_BAUD_TIME_MS * 1e-3),
+                    "GPS initilisation blob is to large to be completely sent before the baud rate changes");
+
     AP_Param::setup_object_defaults(this, var_info);
 }