diff --git a/src/cfgparse.c b/src/cfgparse.c
index 63483cf..e46a4f6 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -133,7 +133,9 @@
 		if (!ss2)
 			goto fail;
 
-		if (ss2->ss_family == AF_INET || ss2->ss_family == AF_INET6) {
+		if (ss2->ss_family == AF_INET || ss2->ss_family == AF_INET6
+		                              || ss2->ss_family == AF_CUST_UDP4
+					      || ss2->ss_family == AF_CUST_UDP6) {
 			if (!port && !end) {
 				memprintf(err, "missing port number: '%s'\n", str);
 				goto fail;