# define kRTPagesLo OBJC_UINTPTR_T(-24 * 0x1000) // i386 0xfffe8000
#elif defined(__x86_64__)
# define kRTPagesLo OBJC_UINTPTR_T(-24 * 0x1000) // x86_64 0xfffffffffffe8000
+#elif defined(__arm__) || defined(TARGET_OS_WIN32)
+# define kRTPagesLo OBJC_UINTPTR_T(0)
#else
#error unknown architecture
#endif