2 files changed, 3 insertions, 11 deletions
diff --git a/nixos/modules/services/networking/networkmanager.nix b/nixos/modules/services/networking/networkmanager.nix
index 72f544c60525..53c847ee3ca2 100644
--- a/nixos/modules/services/networking/networkmanager.nix
+++ b/nixos/modules/services/networking/networkmanager.nix
@@ -35,7 +35,6 @@ let
       rc-manager =
         if config.networking.resolvconf.enable then "resolvconf"
         else "unmanaged";
-      firewall-backend = cfg.firewallBackend;
     })
     (mkSection "keyfile" {
       unmanaged-devices =
@@ -232,15 +231,6 @@ in
         '';
       };
 
-      firewallBackend = mkOption {
-        type = types.enum [ "iptables" "nftables" "none" ];
-        default = "iptables";
-        description = lib.mdDoc ''
-          Which firewall backend should be used for configuring masquerading with shared mode.
-          If set to none, NetworkManager doesn't manage the configuration at all.
-        '';
-      };
-
       logLevel = mkOption {
         type = types.enum [ "OFF" "ERR" "WARN" "INFO" "DEBUG" "TRACE" ];
         default = "WARN";
@@ -412,6 +402,9 @@ in
       them via the DNS server in your network, or use environment.etc
       to add a file into /etc/NetworkManager/dnsmasq.d reconfiguring hostsdir.
     '')
+    (mkRemovedOptionModule [ "networking" "networkmanager" "firewallBackend" ] ''
+      This option was removed as NixOS is now using iptables-nftables-compat even when using iptables, therefore Networkmanager now uses the nftables backend unconditionally.
+    '')
   ];
 
 
diff --git a/nixos/modules/services/networking/nftables.nix b/nixos/modules/services/networking/nftables.nix
index 47159ade328c..a0afdb452752 100644
--- a/nixos/modules/services/networking/nftables.nix
+++ b/nixos/modules/services/networking/nftables.nix
@@ -248,7 +248,6 @@ in
   config = mkIf cfg.enable {
     boot.blacklistedKernelModules = [ "ip_tables" ];
     environment.systemPackages = [ pkgs.nftables ];
-    networking.networkmanager.firewallBackend = mkDefault "nftables";
     # versionOlder for backportability, remove afterwards
     networking.nftables.flushRuleset = mkDefault (versionOlder config.system.stateVersion "23.11" || (cfg.rulesetFile != null || cfg.ruleset != ""));
     systemd.services.nftables = {