diff --git a/src/xenia/xbox.h b/src/xenia/xbox.h
index 998def9ee..93cec9614 100644
--- a/src/xenia/xbox.h
+++ b/src/xenia/xbox.h
@@ -118,18 +118,20 @@ typedef uint32_t X_HRESULT;
 #define X_E_NO_SUCH_USER                        X_HRESULT_FROM_WIN32(X_ERROR_NO_SUCH_USER)
 
 // MEM_*, used by NtAllocateVirtualMemory
-#define X_MEM_COMMIT              0x00001000
-#define X_MEM_RESERVE             0x00002000
-#define X_MEM_DECOMMIT            0x00004000
-#define X_MEM_RELEASE             0x00008000
-#define X_MEM_FREE                0x00010000
-#define X_MEM_PRIVATE             0x00020000
-#define X_MEM_RESET               0x00080000
-#define X_MEM_TOP_DOWN            0x00100000
-#define X_MEM_NOZERO              0x00800000
-#define X_MEM_LARGE_PAGES         0x20000000
-#define X_MEM_HEAP                0x40000000
-#define X_MEM_16MB_PAGES          0x80000000  // from Valve SDK
+enum X_MEM : uint32_t {
+  X_MEM_COMMIT      = 0x00001000,
+  X_MEM_RESERVE     = 0x00002000,
+  X_MEM_DECOMMIT    = 0x00004000,
+  X_MEM_RELEASE     = 0x00008000,
+  X_MEM_FREE        = 0x00010000,
+  X_MEM_PRIVATE     = 0x00020000,
+  X_MEM_RESET       = 0x00080000,
+  X_MEM_TOP_DOWN    = 0x00100000,
+  X_MEM_NOZERO      = 0x00800000,
+  X_MEM_LARGE_PAGES = 0x20000000,
+  X_MEM_HEAP        = 0x40000000,
+  X_MEM_16MB_PAGES  = 0x80000000  // from Valve SDK
+};
 
 // PAGE_*, used by NtAllocateVirtualMemory
 #define X_PAGE_NOACCESS           0x00000001