diff --git a/include/osmocom/mgcp/mgcp_trunk.h b/include/osmocom/mgcp/mgcp_trunk.h
index c6a0997..82728fe 100644
--- a/include/osmocom/mgcp/mgcp_trunk.h
+++ b/include/osmocom/mgcp/mgcp_trunk.h
@@ -50,6 +50,7 @@
 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_name(const struct mgcp_config *cfg, const char *epname);
+int e1_trunk_nr_from_epname(const char *epname);
 
 /* The virtual trunk is always created on trunk id 0 for historical reasons,
  * use this define constant as ID when allocating a virtual trunk. Other