diff --git a/include/osmocom/mgcp/mgcp_msg.h b/include/osmocom/mgcp/mgcp_msg.h
index 7732865..87987d3 100644
--- a/include/osmocom/mgcp/mgcp_msg.h
+++ b/include/osmocom/mgcp/mgcp_msg.h
@@ -39,7 +39,7 @@
 
 int mgcp_parse_osmux_cid(const char *line);
 
-int mgcp_check_param(const struct mgcp_endpoint *endp, const char *line);
+bool mgcp_check_param(const struct mgcp_endpoint *endp, struct mgcp_trunk *trunk, const char *line);
 
 int mgcp_verify_call_id(struct mgcp_endpoint *endp, const char *callid);