diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
index 14d65978c320..028907693a5a 100644
--- a/nixos/modules/services/hardware/udev.nix
+++ b/nixos/modules/services/hardware/udev.nix
@@ -143,7 +143,10 @@ let
       done
 
       echo "Generating hwdb database..."
-      ${udev}/bin/udevadm hwdb --update --root=$(pwd)
+      # hwdb --update doesn't return error code even on errors!
+      res="$(${udev}/bin/udevadm hwdb --update --root=$(pwd) 2>&1)"
+      echo "$res"
+      [ -z "$(echo "$res" | egrep '^Error')" ]
       mv etc/udev/hwdb.bin $out
     '';