diff --git a/srtcore/channel.h b/srtcore/channel.h
index 121248061..648944202 100644
--- a/srtcore/channel.h
+++ b/srtcore/channel.h
@@ -176,6 +176,9 @@ class CChannel
 
 private:
     UDPSOCKET m_iSocket; // socket descriptor
+#ifdef _WIN32
+    mutable WSAOVERLAPPED m_SendOverlapped;
+#endif
 
     // Mutable because when querying original settings
     // this comprises the cache for extracted values,