diff --git a/msg/ActionRequest.msg b/msg/ActionRequest.msg
index 65d101759c8..6723412b5ff 100644
--- a/msg/ActionRequest.msg
+++ b/msg/ActionRequest.msg
@@ -24,3 +24,5 @@ uint8 SOURCE_RC_BUTTON = 2 # Triggered by a momentary button on the RC being pre
 uint8 SOURCE_RC_MODE_SLOT = 3 # Mode change through the RC mode selection mechanism
 
 uint8 mode # Requested mode. Only applies when `action` is `ACTION_SWITCH_MODE`. Values for this field are defined by the `vehicle_status_s::NAVIGATION_STATE_*` enumeration.
+
+uint8 ORB_QUEUE_LENGTH = 4