diff --git a/httplib.h b/httplib.h
index c621f5b53d..f4a6d9cc60 100644
--- a/httplib.h
+++ b/httplib.h
@@ -2910,8 +2910,15 @@ inline bool mmap::open(const char *path) {
 
 #if defined(_WIN32)
   std::wstring wpath;
-  for (size_t i = 0; i < strlen(path); i++) {
-    wpath += path[i];
+  {
+    auto len = static_cast<int>(strlen(path));
+    auto wlen = ::MultiByteToWideChar(CP_UTF8, 0, path, len, nullptr, 0);
+    if (wlen <= 0) { return false; }
+
+    wpath.resize(wlen);
+    auto pwpath = const_cast<LPWSTR>(reinterpret_cast<LPCWSTR>(wpath.data()));
+    wlen = ::MultiByteToWideChar(CP_UTF8, 0, path, len, pwpath, wlen);
+    if (wlen != wpath.size()) { return false; }
   }
 
 #if _WIN32_WINNT >= _WIN32_WINNT_WIN8
diff --git a/test/test.cc b/test/test.cc
index 154b60c5e2..dfa4e1a14e 100644
--- a/test/test.cc
+++ b/test/test.cc
@@ -5271,6 +5271,27 @@ TEST(MountTest, Redicect) {
   EXPECT_EQ(StatusCode::OK_200, res->status);
 }
 
+TEST(MountTest, MultibytesPathName) {
+  Server svr;
+
+  auto listen_thread = std::thread([&svr]() { svr.listen("localhost", PORT); });
+  auto se = detail::scope_exit([&] {
+    svr.stop();
+    listen_thread.join();
+    ASSERT_FALSE(svr.is_running());
+  });
+
+  svr.set_mount_point("/", "./www");
+  svr.wait_until_ready();
+
+  Client cli("localhost", PORT);
+
+  auto res = cli.Get("/日本語Dir/日本語File.txt");
+  ASSERT_TRUE(res);
+  EXPECT_EQ(StatusCode::OK_200, res->status);
+  EXPECT_EQ("日本語コンテンツ", res->body);
+}
+
 TEST(KeepAliveTest, ReadTimeout) {
   Server svr;
 
diff --git "a/test/www/\346\227\245\346\234\254\350\252\236Dir/\346\227\245\346\234\254\350\252\236File.txt" "b/test/www/\346\227\245\346\234\254\350\252\236Dir/\346\227\245\346\234\254\350\252\236File.txt"
new file mode 100644
index 0000000000..3cc1ce7c92
--- /dev/null
+++ "b/test/www/\346\227\245\346\234\254\350\252\236Dir/\346\227\245\346\234\254\350\252\236File.txt"
@@ -0,0 +1 @@
+日本語コンテンツ
\ No newline at end of file