diff --git a/src/key_defs_keymaps.h b/src/key_defs_keymaps.h
index 7c5d3b48..c0dda0f9 100644
--- a/src/key_defs_keymaps.h
+++ b/src/key_defs_keymaps.h
@@ -1,6 +1,7 @@
 #pragma once
 
-#define MOMENTARY_OFFSET 42
+static const uint8_t MOMENTARY_OFFSET __attribute__((deprecated)) = 42;
+static const uint8_t LAYER_SHIFT_OFFSET = 42;
 
 #define KEYMAP_0     0
 #define KEYMAP_1     1
@@ -22,15 +23,15 @@
 #define Key_Keymap3 (Key) { KEYMAP_3,  KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP  }
 #define Key_Keymap4 (Key) { KEYMAP_4,  KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP  }
 #define Key_Keymap5 (Key) { KEYMAP_5,  KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP  }
-#define Key_Keymap0_Momentary (Key){ KEYMAP_0 + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
-#define Key_Keymap1_Momentary (Key){ KEYMAP_1 + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
-#define Key_Keymap2_Momentary (Key){ KEYMAP_2 + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
-#define Key_Keymap3_Momentary (Key){ KEYMAP_3 + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
-#define Key_Keymap4_Momentary (Key){ KEYMAP_4 + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
-#define Key_Keymap5_Momentary (Key){ KEYMAP_5 + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_Keymap0_Momentary (Key){ KEYMAP_0 + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_Keymap1_Momentary (Key){ KEYMAP_1 + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_Keymap2_Momentary (Key){ KEYMAP_2 + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_Keymap3_Momentary (Key){ KEYMAP_3 + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_Keymap4_Momentary (Key){ KEYMAP_4 + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_Keymap5_Momentary (Key){ KEYMAP_5 + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
 
-#define Key_KeymapNext_Momentary (Key) { KEYMAP_NEXT + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
-#define Key_KeymapPrevious_Momentary (Key) { KEYMAP_PREVIOUS + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_KeymapNext_Momentary (Key) { KEYMAP_NEXT + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define Key_KeymapPrevious_Momentary (Key) { KEYMAP_PREVIOUS + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
 
 
 /** Lock/Unlock layer `n`.
@@ -47,4 +48,4 @@
  * released, the layer shifts back too. `n` can be a number, or an enum
  * value declared previously.
  */
-#define ShiftToLayer(n) (Key){ n + MOMENTARY_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
+#define ShiftToLayer(n) (Key){ n + LAYER_SHIFT_OFFSET, KEY_FLAGS | SYNTHETIC | SWITCH_TO_KEYMAP }
diff --git a/src/layers.cpp b/src/layers.cpp
index 35a9f7dd..702672a8 100644
--- a/src/layers.cpp
+++ b/src/layers.cpp
@@ -9,8 +9,8 @@ uint8_t Layer_::activeLayers[ROWS][COLS];
 Key(*Layer_::getKey)(uint8_t layer, byte row, byte col) = Layer.getKeyFromPROGMEM;
 
 static void handleKeymapKeyswitchEvent(Key keymapEntry, uint8_t keyState) {
-  if (keymapEntry.keyCode >= MOMENTARY_OFFSET) {
-    uint8_t target = keymapEntry.keyCode - MOMENTARY_OFFSET;
+  if (keymapEntry.keyCode >= LAYER_SHIFT_OFFSET) {
+    uint8_t target = keymapEntry.keyCode - LAYER_SHIFT_OFFSET;
 
     switch (target) {
     case KEYMAP_NEXT: