diff --git a/libc/kernel/arch-x86/asm/cmpxchg.h b/libc/kernel/arch-x86/asm/cmpxchg.h
index 9447850..c26890c 100644
--- a/libc/kernel/arch-x86/asm/cmpxchg.h
+++ b/libc/kernel/arch-x86/asm/cmpxchg.h
@@ -16,4 +16,9 @@
  ***
  ****************************************************************************
  ****************************************************************************/
+#ifdef __i386__
 #include "cmpxchg_32.h"
+#else
+#include "cmpxchg_64.h"
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#endif