diff --git a/compat/poll/poll.c b/compat/poll/poll.c
index 7d226ecb29..44103103a4 100644
--- a/compat/poll/poll.c
+++ b/compat/poll/poll.c
@@ -576,7 +576,7 @@ poll (struct pollfd *pfd, nfds_t nfd, int timeout)
 	{
 	  /* It's a socket.  */
 	  WSAEnumNetworkEvents ((SOCKET) h, NULL, &ev);
-	  WSAEventSelect ((SOCKET) h, 0, 0);
+	  WSAEventSelect ((SOCKET) h, NULL, 0);
 
 	  /* If we're lucky, WSAEnumNetworkEvents already provided a way
 	     to distinguish FD_READ and FD_ACCEPT; this saves a recv later.  */