Index: lib/builtins/int_types.h
===================================================================
--- lib/builtins/int_types.h
+++ lib/builtins/int_types.h
@@ -60,7 +60,8 @@
     }s;
 } udwords;
 
-#if (defined(__LP64__) || defined(__wasm__) || defined(__mips64))
+#if (defined(__LP64__) || defined(__wasm__) || defined(__mips64) || \
+     (defined(_MSC_VER) && defined(_WIN64)))
 #define CRT_HAS_128BIT
 #endif