diff --git a/include/osmocom/mgcp/mgcp_trunk.h b/include/osmocom/mgcp/mgcp_trunk.h
index 82728fe..aa6dd29 100644
--- a/include/osmocom/mgcp/mgcp_trunk.h
+++ b/include/osmocom/mgcp/mgcp_trunk.h
@@ -48,7 +48,7 @@
 
 struct mgcp_trunk *mgcp_trunk_alloc(struct mgcp_config *cfg, enum mgcp_trunk_type ttype, int nr);
 int mgcp_trunk_alloc_endpts(struct mgcp_trunk *tcfg);
-struct mgcp_trunk *mgcp_trunk_by_num(const struct mgcp_config *cfg, int index);
+struct mgcp_trunk *mgcp_trunk_by_num(const struct mgcp_config *cfg, enum mgcp_trunk_type ttype, int nr);
 struct mgcp_trunk *mgcp_trunk_by_name(const struct mgcp_config *cfg, const char *epname);
 int e1_trunk_nr_from_epname(const char *epname);