diff --git a/nixos/modules/virtualisation/nixos-containers.nix b/nixos/modules/virtualisation/nixos-containers.nix
index 84bb0b6c4856..dd9177a5bd21 100644
--- a/nixos/modules/virtualisation/nixos-containers.nix
+++ b/nixos/modules/virtualisation/nixos-containers.nix
@@ -607,14 +607,16 @@ in
                                 boot.isNspawnContainer = true;
                                 networking.hostName = mkDefault name;
                                 networking.useDHCP = false;
-                                networking.interfaces = lib.mkIf config.privateNetwork {
-                                  eth0.ipv4.addresses = lib.optional (config.localAddress != null) (
-                                    ipv4FromString config.localAddress
-                                  );
-                                  eth0.ipv6.addresses = lib.optional (config.localAddress6 != null) (
-                                    lib.network.ipv6.fromString config.localAddress6
-                                  );
-                                };
+                                networking.interfaces = lib.mkIf config.privateNetwork (
+                                  lib.mkMerge [
+                                    (lib.mkIf (config.localAddress != null) {
+                                      eth0.ipv4.addresses = [ (ipv4FromString config.localAddress) ];
+                                    })
+                                    (lib.mkIf (config.localAddress6 != null) {
+                                      eth0.ipv6.addresses = [ (lib.network.ipv6.fromString config.localAddress6) ];
+                                    })
+                                  ]
+                                );
                                 assertions = [
                                   {
                                     assertion =