diff --git a/host_tools/package_tool b/host_tools/package_tool
index 1454c2e..c3b2f27 100755
--- a/host_tools/package_tool
+++ b/host_tools/package_tool
@@ -28,7 +28,7 @@ def package(package_name, car_id, feature_number):
     # Create package to match defined structure on fob
     package_message_bytes = (
         str.encode(car_id + car_id_pad)
-        + feature_number.to_bytes(1, "little")
+        + (feature_number & 0xff).to_bytes(1, "little")
         + str.encode("\n")
     )