diff --git a/hosts/carbon/configuration.nix b/hosts/carbon/configuration.nix
index 3c9b480..d877a9e 100644
--- a/hosts/carbon/configuration.nix
+++ b/hosts/carbon/configuration.nix
@@ -58,9 +58,6 @@
   };
 
   clerie.firewall.enable = true;
-  clerie.firewall.extraForwardMangleCommands = ''
-    ip46tables -t mangle -A forward-mangle -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1416
-  '';
 
   clerie.monitoring = {
     enable = true;
diff --git a/hosts/carbon/ppp.nix b/hosts/carbon/ppp.nix
index 7c09f21..a97289e 100644
--- a/hosts/carbon/ppp.nix
+++ b/hosts/carbon/ppp.nix
@@ -53,4 +53,8 @@
     ];
   };
 
+  clerie.firewall.extraForwardMangleCommands = ''
+    ip46tables -t mangle -A forward-mangle -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1416
+  '';
+
 }