diff --git a/cocos/2d/platform/win32/CCFileUtilsWin32.cpp b/cocos/2d/platform/win32/CCFileUtilsWin32.cpp
index a5c94dac90..216797bd9e 100644
--- a/cocos/2d/platform/win32/CCFileUtilsWin32.cpp
+++ b/cocos/2d/platform/win32/CCFileUtilsWin32.cpp
@@ -121,7 +121,7 @@ bool FileUtilsWin32::isAbsolutePath(const std::string& strPath) const
     return false;
 }
 
-unsigned char* FileUtilsWin32::getFileData(const char* filename, const char* mode, unsigned long* size)
+unsigned char* FileUtilsWin32::getFileData(const char* filename, const char* mode, long* size)
 {
     unsigned char * pBuffer = NULL;
     CCASSERT(filename != NULL && size != NULL && mode != NULL, "Invalid parameters.");
diff --git a/cocos/2d/platform/win32/CCFileUtilsWin32.h b/cocos/2d/platform/win32/CCFileUtilsWin32.h
index 4f01adabeb..5c88d97cf9 100644
--- a/cocos/2d/platform/win32/CCFileUtilsWin32.h
+++ b/cocos/2d/platform/win32/CCFileUtilsWin32.h
@@ -58,7 +58,7 @@ protected:
      *  @return Upon success, a pointer to the data is returned, otherwise NULL.
      *  @warning Recall: you are responsible for calling delete[] on any Non-NULL pointer returned.
      */
-    virtual unsigned char* getFileData(const char* filename, const char* mode, unsigned long * size) override;
+    virtual unsigned char* getFileData(const char* filename, const char* mode, long * size) override;
 
     /**
      *  Gets full path for filename, resolution directory and search path.