1 files changed, 2 insertions, 2 deletions

diff --git a/src/uniquekey.h b/src/uniquekey.h
index 015fbf2..7162753 100644
--- a/src/uniquekey.h
+++ b/src/uniquekey.h
@@ -11,9 +11,9 @@ struct s_UniqueKey
 typedef struct s_UniqueKey UniqueKey;
 
 #if LUAJIT_FLAVOR() == 64 // building against LuaJIT headers for 64 bits, light userdata is restricted to 47 significant bits, because LuaJIT uses the other bits for internal optimizations
-#define MAKE_UNIQUE_KEY( p_) ((void*)((ptrdiff_t)(p_) & 0x7fffffffffffull))
+#define MAKE_UNIQUE_KEY( p_) ((void*)((uintptr_t)(p_) & 0x7fffffffffffull))
 #else // LUAJIT_FLAVOR()
-#define MAKE_UNIQUE_KEY( p_) ((void*)(ptrdiff_t)(p_))
+#define MAKE_UNIQUE_KEY( p_) ((void*)(uintptr_t)(p_))
 #endif // LUAJIT_FLAVOR()
 
 #define DECLARE_UNIQUE_KEY( name_) UniqueKey name_