diff --git a/httplib.h b/httplib.h
index 7ef5826..2a4b285 100644
--- a/httplib.h
+++ b/httplib.h
@@ -2859,8 +2859,7 @@ inline bool mmap::open(const char *path) {
   hMapping_ =
       ::CreateFileMappingFromApp(hFile_, NULL, PAGE_READONLY, size_, NULL);
 #else
-  hMapping_ = ::CreateFileMappingW(hFile_, NULL, PAGE_READONLY, size.HighPart,
-                                   size.LowPart, NULL);
+  hMapping_ = ::CreateFileMappingW(hFile_, NULL, PAGE_READONLY, 0, 0, NULL);
 #endif
 
   if (hMapping_ == NULL) {