diff --git a/tmk_core/common.mk b/tmk_core/common.mk
index cb030b33..3b53c0a0 100644
--- a/tmk_core/common.mk
+++ b/tmk_core/common.mk
@@ -53,6 +53,10 @@ ifdef USB_6KRO_ENABLE
     OPT_DEFS += -DUSB_6KRO_ENABLE
 endif
 
+ifdef KEYBOARD_LOCK_ENABLE
+    OPT_DEFS += -DKEYBOARD_LOCK_ENABLE
+endif
+
 ifdef SLEEP_LED_ENABLE
     SRC += $(COMMON_DIR)/sleep_led.c
     OPT_DEFS += -DSLEEP_LED_ENABLE