diff --git a/lib/plat/windows/windows-sockets.c b/lib/plat/windows/windows-sockets.c
index 065d5c245..38910fcc5 100644
--- a/lib/plat/windows/windows-sockets.c
+++ b/lib/plat/windows/windows-sockets.c
@@ -47,7 +47,7 @@ lws_plat_set_nonblocking(int fd)
 {
 	u_long optl = 1;
 	int result = !!ioctlsocket(fd, FIONBIO, &optl);
-	if (!result)
+	if (result)
 	{
 		int error = LWS_ERRNO;
 		lwsl_err("ioctlsocket FIONBIO 1 failed with error %d\n", error);