diff --git a/nixos/modules/system/boot/networkd.nix b/nixos/modules/system/boot/networkd.nix
index 07f51f43184d..463e2b8d90b0 100644
--- a/nixos/modules/system/boot/networkd.nix
+++ b/nixos/modules/system/boot/networkd.nix
@@ -25,9 +25,11 @@ let
 
       sectionDHCPv4 = checkUnitConfig "DHCPv4" [
         (assertOnlyFields [
+          "ClientIdentifier"
           "DUIDType"
           "DUIDRawData"
         ])
+        (assertValueOneOf "ClientIdentifier" ["mac" "duid" "duid-only"])
       ];
 
       sectionDHCPv6 = checkUnitConfig "DHCPv6" [