diff --git a/include/osmocom/msc/call_leg.h b/include/osmocom/msc/call_leg.h
index d8380f5..f35816c 100644
--- a/include/osmocom/msc/call_leg.h
+++ b/include/osmocom/msc/call_leg.h
@@ -44,6 +44,8 @@
 
 	/* Prevent events from deallocating for certain release code paths, to prevent use-after-free problems. */
 	bool deallocating;
+
+	bool ran_peer_supports_osmux;
 };
 
 enum call_leg_event {