This consumes about 5390 bytes.
+`KEY_LOCK_ENABLE`
+
+This enables [key lock](key_lock.md). This consumes an additional 260 bytes.
+
## Customizing Makefile options on a per-keymap basis
If your keymap directory has a file called `Makefile` (note the filename), any Makefile options you set in that file will take precedence over other Makefile options for your particular keyboard.