diff --git a/library/amd64_windows/include/HCNetSDK.h b/library/amd64_windows/include/HCNetSDK.h
index 599fcde..49739ca 100644
--- a/library/amd64_windows/include/HCNetSDK.h
+++ b/library/amd64_windows/include/HCNetSDK.h
@@ -28,7 +28,7 @@
 #endif
 
 #if (defined(_WIN32)) //windows
-    #define NET_DVR_API  extern "C" __declspec(dllimport)
+    #define NET_DVR_API
     typedef  unsigned __int64   UINT64;
     typedef  signed   __int64   INT64;
 #elif defined(__linux__) || defined(__APPLE__) //linux