diff --git a/postfix.nix b/postfix.nix
index 787aba5..7521826 100644
--- a/postfix.nix
+++ b/postfix.nix
@@ -7,7 +7,7 @@
     ip6tables -A OUTPUT -m owner ! --uid-owner ${user} -m tcp -p tcp --dport 25 -j REJECT --reject-with icmp6-adm-prohibited
 
     iptables -I OUTPUT -m tcp -p tcp --dport 25 -d 127.0.0.1 -j ACCEPT
-    ip6tables -I OUTPUT -m tcp -p tcp --dport 25 -d 127.0.0.1 -j ACCEPT
+    ip6tables -I OUTPUT -m tcp -p tcp --dport 25 -d ::1 -j ACCEPT
   '';
 
   services.postfix = {