diff --git a/libraries/AP_Vehicle/ModeReason.h b/libraries/AP_Vehicle/ModeReason.h
index b78fa369a5..49524b7490 100644
--- a/libraries/AP_Vehicle/ModeReason.h
+++ b/libraries/AP_Vehicle/ModeReason.h
@@ -60,4 +60,5 @@ enum class ModeReason : uint8_t {
   RTL_COMPLETE_SWITCHING_TO_FIXEDWING_AUTOLAND,
   MISSION_CMD,
   FRSKY_COMMAND,
+  FENCE_RETURN_PREVIOUS_MODE,
 };