diff --git a/libc/private/CFIShadow.h b/libc/private/CFIShadow.h
index 9f980f8..26351db 100644
--- a/libc/private/CFIShadow.h
+++ b/libc/private/CFIShadow.h
@@ -62,7 +62,7 @@
   static constexpr uintptr_t kCfiCheckAlign = 1UL << kCfiCheckGranularity;  // 4K
 
 #if defined(__aarch64__)
-  static constexpr uintptr_t kMaxTargetAddr = 0xffffffffffff;
+  static constexpr uintptr_t kMaxTargetAddr = 0x7fffffffff;
 #elif defined (__LP64__)
   static constexpr uintptr_t kMaxTargetAddr = 0x7fffffffffff;
 #else