diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index 1c35aa9..7e07d00 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -180,6 +180,9 @@
 		   &r->audio_port) != 1)
 		goto response_parse_failure;
 
+	if (r->audio_port == 0)
+		goto response_parse_failure;
+
 	return 0;
 
 response_parse_failure: