diff --git a/source/core/FileLoader.cpp b/source/core/FileLoader.cpp
index 1b183ea5e..19d05006b 100644
--- a/source/core/FileLoader.cpp
+++ b/source/core/FileLoader.cpp
@@ -14,7 +14,7 @@ namespace MNN {
 static FILE* _OpenFile(const char* file, bool read) {
 #if defined(_MSC_VER)
     wchar_t wFilename[1024];
-    if (0 == MultiByteToWideChar(CP_ACP, 0, file, -1, wFilename, sizeof(wFilename))) {
+    if (0 == MultiByteToWideChar(CP_UTF8, 0, file, -1, wFilename, sizeof(wFilename))) {
         return nullptr;
     }
 #if _MSC_VER >= 1400