diff --git a/include/osmocom/mgcp/mgcp_trunk.h b/include/osmocom/mgcp/mgcp_trunk.h
index 2bd55e63c..c6a099723 100644
--- a/include/osmocom/mgcp/mgcp_trunk.h
+++ b/include/osmocom/mgcp/mgcp_trunk.h
@@ -11,7 +11,7 @@ struct mgcp_trunk {
 	struct mgcp_config *cfg;
 
 	int trunk_nr;
-	int trunk_type;
+	enum mgcp_trunk_type trunk_type;
 
 	char *audio_fmtp_extra;
 	int audio_send_ptime;