diff --git a/common/keymap_ex.c b/common/keymap_ex.c
index cb67e8f4..3d55c08c 100644
--- a/common/keymap_ex.c
+++ b/common/keymap_ex.c
@@ -32,6 +32,12 @@ void keymap_init(void) {
 bool check_keymap_in_eeprom(void) {
     uint16_t checksum_in_eeprom = eeprom_read_word(&((keymap_ex_t*)EECONFIG_KEYMAP_EX)->checksum);
     uint16_t checksum = EECONFIG_MAGIC_NUMBER;
+    for (uint16_t i = 0; i < KEYMAP_SIZE; i += 2) {
+        checksum ^= eeprom_read_word((void*)(EECONFIG_KEYMAP_FN_ACTIONS + i));
+    }
+#ifdef DEBUG
+    eeprom_write_word((void*)(EECONFIG_KEYMAP_DEBUG), checksum);
+#endif
     return (checksum_in_eeprom == checksum);
 }
 
diff --git a/common/keymap_ex.h b/common/keymap_ex.h
index be229b10..435547a0 100644
--- a/common/keymap_ex.h
+++ b/common/keymap_ex.h
@@ -33,11 +33,13 @@ typedef struct {
     uint8_t keymaps[KEYMAPS_COUNT][MATRIX_ROWS][MATRIX_COLS];
 } keymap_ex_t;
 
+#define EECONFIG_KEYMAP_DEBUG (EECONFIG_KEYMAP_EX - sizeof(uint16_t))
 #define EECONFIG_KEYMAP_CHECKSUM (EECONFIG_KEYMAP_EX)
 #define EECONFIG_KEYMAP_FN_ACTIONS (EECONFIG_KEYMAP_EX + sizeof(uint16_t))
 #define EECONFIG_KEYMAP_KEYMAPS (EECONFIG_KEYMAP_FN_ACTIONS + sizeof(uint16_t) * FN_ACTIONS_COUNT)
 
 #define KEYS_COUNT (KEYMAPS_COUNT * MATRIX_ROWS * MATRIX_COLS)
+#define KEYMAP_SIZE (sizeof(uint16_t) * FN_ACTIONS_COUNT + sizeof(uint8_t) * KEYS_COUNT)
 #define FN_ACTION_OFFSET(index) (sizeof(uint16_t) * index)
 #define KEY_OFFSET(layer, row, col) (sizeof(uint8_t) * (layer * MATRIX_ROWS * MATRIX_COLS + row * MATRIX_COLS + col))