diff --git a/include/constants/heap.h b/include/constants/heap.h
index 5d29c71fa9..6009ceaf85 100644
--- a/include/constants/heap.h
+++ b/include/constants/heap.h
@@ -2,7 +2,7 @@
 #define POKEPLATINUM_CONSTANTS_HEAP_H
 
 enum HeapId {
-    HEAP_ID_SYSTEM,
+    HEAP_ID_SYSTEM = 0,
     HEAP_ID_SAVE,
     HEAP_ID_DEBUG,
     HEAP_ID_APPLICATION,