diff --git a/hosts/containers/auth/default.nix b/hosts/containers/auth/default.nix
index 5af84004..2d523e7f 100644
--- a/hosts/containers/auth/default.nix
+++ b/hosts/containers/auth/default.nix
@@ -17,7 +17,11 @@
       "::1" = [ "auth.c3d2.de" ];
       "127.0.0.1" = [ "auth.c3d2.de" ];
     };
-    firewall.allowedTCPPorts = [ 80 443 ];
+    firewall.allowedTCPPorts = [
+      80  # http
+      443 # https
+      636 # ldaps
+    ];
   };
 
   services = {