diff --git a/reactos/drivers/net/tcpip/transport/tcp/event.c b/reactos/drivers/net/tcpip/transport/tcp/event.c
index e014d9a79f3..f29f5bbd47d 100644
--- a/reactos/drivers/net/tcpip/transport/tcp/event.c
+++ b/reactos/drivers/net/tcpip/transport/tcp/event.c
@@ -13,7 +13,6 @@
 extern ULONG TCP_IPIdentification;
 extern LIST_ENTRY SleepingThreadsList;
 extern FAST_MUTEX SleepingThreadsLock;
-extern RECURSIVE_MUTEX TcpMutex;
 
 int TCPSocketState(void *ClientData,
 		   void *WhichSocket,