diff --git a/minimal_heap.h b/minimal_heap.h
index fd5c0cf..a7877e7 100644
--- a/minimal_heap.h
+++ b/minimal_heap.h
@@ -97,7 +97,13 @@ typedef struct _MIHP_HeapMemoryAreaHeader
 
 typedef struct _MIHP_AllocationCustomMetadata
 {
-	uint8_t data[16];
+	union
+	{
+		uint8_t		AsU8	[sizeof(size_t) * 2];
+		uint16_t	AsU16	[sizeof(size_t) * 1];
+		uint32_t	AsU32	[sizeof(size_t) / 2];
+		uint64_t	AsU64	[sizeof(size_t) / 4];
+	};
 } MIHP_AllocationCustomMetadata;
 
 typedef struct _MIHP_HeapSegmentHeader
diff --git a/minimal_heap_test.cpp b/minimal_heap_test.cpp
index 7f57335..ff0e663 100644
--- a/minimal_heap_test.cpp
+++ b/minimal_heap_test.cpp
@@ -62,7 +62,7 @@ int main()
 
 		MIHP_AllocationCustomMetadata metadata = { 0 };
 		void* ptr = GetThisAddress();
-		memcpy(&metadata.data, &ptr, sizeof(void*));
+		memcpy(&metadata.AsU8, &ptr, sizeof(void*));
 
 		MIHP_SetPointerCustomMetadata(&myHeap, myptrs[i], metadata);
 		MIHP_ValidateHeap(&myHeap);
@@ -71,7 +71,7 @@ int main()
 		MIHP_GetPointerCustomMetadata(&myHeap, myptrs[i], &outMetadata);
 		void* returnPtr;
 
-		memcpy(&returnPtr, &outMetadata.data, sizeof(void*));
+		memcpy(&returnPtr, &outMetadata.AsU8, sizeof(void*));
 
 		MIHP_ASSERT(ptr == returnPtr);
 #endif