diff --git a/include/constants/item_config.h b/include/constants/item_config.h
index 4f111bc0ca..e78f748fa9 100644
--- a/include/constants/item_config.h
+++ b/include/constants/item_config.h
@@ -1,9 +1,6 @@
 #ifndef GUARD_CONSTANTS_ITEM_CONFIG_H
 #define GUARD_CONSTANTS_ITEM_CONFIG_H
 
-// Used by other branches to communicate with each other.
-#define ITEM_EXPANSION
-
 #ifndef GEN_3
 #define GEN_3 0
 #define GEN_4 1
diff --git a/include/global.h b/include/global.h
index 85166e0ecc..031a2fa759 100644
--- a/include/global.h
+++ b/include/global.h
@@ -112,6 +112,12 @@
     f;                       \
 })
 
+// Branch defines: Used by other branches to detect each other.
+// Each define must be here for each of RHH's branch you have pulled.
+// e.g. If you have both the battle_engine and pokemon_expansion branch,
+//      then both BATTLE_ENGINE and POKEMON_EXPANSION must be defined here.
+#define ITEM_EXPANSION
+
 #define ROUND_BITS_TO_BYTES(numBits)(((numBits) / 8) + (((numBits) % 8) ? 1 : 0))
 
 #define DEX_FLAGS_NO (ROUND_BITS_TO_BYTES(NUM_SPECIES))