diff --git a/net/connUDP_internal_test.go b/net/connUDP_internal_test.go
index 5e1cf901..6d7b160d 100644
--- a/net/connUDP_internal_test.go
+++ b/net/connUDP_internal_test.go
@@ -284,21 +284,29 @@ func TestControlMessageString(t *testing.T) {
 func getIfaceAddr(t *testing.T, iface net.Interface, ipv4 bool) net.IP {
 	addrs, err := iface.Addrs()
 	require.NoError(t, err)
+	require.NotEmpty(t, addrs)
+	var ipOut net.IP
 	for _, addr := range addrs {
 		ip, _, err := net.ParseCIDR(addr.String())
 		require.NoError(t, err)
 		if !ip.IsPrivate() {
 			continue
 		}
-		if ipv4 {
-			if ip.To4() != nil {
-				return ip
-			}
+		if ipv4 && ip.To4() == nil {
 			continue
 		}
-		return ip
+		ipOut = ip
+		break
+	}
+	require.NotEmpty(t, ipOut)
+	return ipOut
+}
+
+func isActiveMulticastInterface(iface net.Interface) bool {
+	if iface.Name == "anpi0" || iface.Name == "anpi1" { // special debugging interfaces on macOS
+		return false
 	}
-	return nil
+	return iface.Flags&net.FlagUp == net.FlagUp && iface.Flags&net.FlagMulticast == net.FlagMulticast && iface.Flags&net.FlagLoopback != net.FlagLoopback
 }
 
 func TestUDPConnWriteToAddr(t *testing.T) {
@@ -306,7 +314,8 @@ func TestUDPConnWriteToAddr(t *testing.T) {
 	require.NoError(t, err)
 	var iface net.Interface
 	for _, i := range ifaces {
-		if i.Flags&net.FlagUp == net.FlagUp && i.Flags&net.FlagMulticast == net.FlagMulticast && i.Flags&net.FlagLoopback != net.FlagLoopback {
+		t.Logf("interface name:%v, flags: %v", i.Name, i.Flags)
+		if isActiveMulticastInterface(i) {
 			iface = i
 			break
 		}