-MOUSEKEY_ENABLE = yes # Mouse keys
-EXTRAKEY_ENABLE = yes # Audio control and System control
-CONSOLE_ENABLE = yes # Console for debug
-COMMAND_ENABLE = yes # Commands for debug and configuration
-#NKRO_ENABLE = yes # USB Nkey Rollover
-UNIMAP_ENABLE = yes
+MOUSEKEY_ENABLE ?= yes # Mouse keys
+EXTRAKEY_ENABLE ?= yes # Audio control and System control
+CONSOLE_ENABLE ?= yes # Console for debug
+COMMAND_ENABLE ?= yes # Commands for debug and configuration
+#NKRO_ENABLE ?= yes # USB Nkey Rollover
+UNIMAP_ENABLE ?= yes