diff --git a/modules/clan/phonebox/default.nix b/modules/clan/phonebox/default.nix
index b04f6aa..d0e3931 100644
--- a/modules/clan/phonebox/default.nix
+++ b/modules/clan/phonebox/default.nix
@@ -323,6 +323,8 @@
 
                       [base_endpoint](!)
                       type=endpoint
+                      transport=transport-udp
+                      transport=transport-udp6
                       disallow=all
                       allow=ulaw,alaw,g722,gsm
                       direct_media=no