diff --git a/modules/ppp/l2tp.nix b/modules/ppp/l2tp.nix
index 10308d11..0ac4d42d 100644
--- a/modules/ppp/l2tp.nix
+++ b/modules/ppp/l2tp.nix
@@ -65,6 +65,7 @@ let
         "ipparam" name
         "nodetach"
         "usepeerdns"
+        "nodefaultroute"
         "logfd" "2"
        ];
 
diff --git a/modules/ppp/pppoe.nix b/modules/ppp/pppoe.nix
index 7a575ccb..e775f2ac 100644
--- a/modules/ppp/pppoe.nix
+++ b/modules/ppp/pppoe.nix
@@ -64,6 +64,7 @@ let
         "ipparam" name
         "nodetach"
         "usepeerdns"
+        "nodefaultroute"
         "logfd" "2"
        ];
   timeoutOpt = if lcpEcho.interval != null then "-T ${builtins.toString (4 * lcpEcho.interval)}" else "";