diff --git a/right/src/main.c b/right/src/main.c
index 38bbeea..38165fd 100644
--- a/right/src/main.c
+++ b/right/src/main.c
@@ -50,7 +50,7 @@ void UpdateUsbReports()
 
     KeyMatrix_Scan(&KeyMatrix);
 
-    memcpy(CurrentKeyStates[SLOT_ID_RIGHT_KEYBOARD_HALF], KeyMatrix.keyStates, MAX_KEY_COUNT_PER_MODULE);
+    memcpy(CurrentKeyStates[SlotId_RightKeyboardHalf], KeyMatrix.keyStates, MAX_KEY_COUNT_PER_MODULE);
     UpdateActiveUsbReports();
 
     SwitchActiveUsbBasicKeyboardReport();
diff --git a/right/src/slave_drivers/uhk_module_driver.c b/right/src/slave_drivers/uhk_module_driver.c
index 3b944d9..eee1284 100644
--- a/right/src/slave_drivers/uhk_module_driver.c
+++ b/right/src/slave_drivers/uhk_module_driver.c
@@ -47,7 +47,7 @@ status_t UhkModuleSlaveDriver_Update(uint8_t uhkModuleId)
             break;
         case UhkModulePhase_ProcessKeystates:
             if (CRC16_IsMessageValid(&rxMessage)) {
-                BoolBitsToBytes(rxMessage.data, CurrentKeyStates[SLOT_ID_LEFT_KEYBOARD_HALF], LEFT_KEYBOARD_HALF_KEY_COUNT);
+                BoolBitsToBytes(rxMessage.data, CurrentKeyStates[SlotId_LeftKeyboardHalf], LEFT_KEYBOARD_HALF_KEY_COUNT);
             }
             status = kStatus_Uhk_NoOp;
             uhkModulePhase = UhkModulePhase_SetTestLed;
diff --git a/right/src/slot.h b/right/src/slot.h
index d4d462e..cb66b63 100644
--- a/right/src/slot.h
+++ b/right/src/slot.h
@@ -12,11 +12,15 @@
 
 // Macros:
 
-    #define SLOT_ID_RIGHT_KEYBOARD_HALF 0
-    #define SLOT_ID_LEFT_KEYBOARD_HALF  1
-    #define SLOT_ID_LEFT_MODULE         2
-    #define SLOT_ID_RIGHT_MODULE        3
-
     #define SLOT_COUNT 4
 
+// Typedefs:
+
+    typedef enum {
+        SlotId_RightKeyboardHalf = 0,
+        SlotId_LeftKeyboardHalf  = 1,
+        SlotId_LeftModule        = 2,
+        SlotId_RightModule       = 3,
+    } slot_t;
+
 #endif