diff --git a/curacao/co2meter/default.nix b/curacao/co2meter/default.nix
index 1c4c784..8f8357b 100644
--- a/curacao/co2meter/default.nix
+++ b/curacao/co2meter/default.nix
@@ -32,9 +32,12 @@ let
     installPhase = ''
       mkdir -p $out/lib/udev/rules.d
       cp udev/90-usb-zytemp-permissions.rules $out/lib/udev/rules.d/90-usb-zytemp.rules
-      sed -i 's|"usb"|"hidraw"|' $out/lib/udev/rules.d/90-usb-zytemp.rules
+      sed 's|"usb"|"hidraw"|' $out/lib/udev/rules.d/90-usb-zytemp.rules >> $out/lib/udev/rules.d/90-usb-zytemp.rules
     '';
+    # hidraw rule was needed for 24.11, apparently it alone doesn't work in 25.05,
+    # keeping both just in case.
   };
+
   mqtt_host = "192.168.7.53"; # Ludwig
 in
 {