diff --git a/nixos/modules/system/boot/networkd.nix b/nixos/modules/system/boot/networkd.nix
index d1a6f46bfc40..0336930b3ab7 100644
--- a/nixos/modules/system/boot/networkd.nix
+++ b/nixos/modules/system/boot/networkd.nix
@@ -779,6 +779,7 @@ let
           "RouteDenyList"
           "RouteAllowList"
           "DHCPv6Client"
+          "RouteMetric"
         ])
         (assertValueOneOf "UseDNS" boolValues)
         (assertValueOneOf "UseDomains" (boolValues ++ ["route"]))