diff --git a/ArduPlane/defines.h b/ArduPlane/defines.h
index 3cdf63d37e..160bb63c87 100644
--- a/ArduPlane/defines.h
+++ b/ArduPlane/defines.h
@@ -162,7 +162,7 @@ enum log_messages {
 #define MASK_LOG_RC                     (1<<13)
 #define MASK_LOG_SONAR                  (1<<14)
 #define MASK_LOG_ARM_DISARM             (1<<15)
-#define MASK_LOG_WHEN_DISARMED          (1<<30)
+#define MASK_LOG_WHEN_DISARMED          (1UL<<30)
 
 // Waypoint Modes
 // ----------------