diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 00bf948..a3c1d98 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -571,15 +571,15 @@
         finally:
             sock.close()
 
+    @unittest.skipUnless(os.name == "nt", "Windows specific")
     def test_sock_ioctl(self):
-        if os.name != "nt":
-            return
         self.assertTrue(hasattr(socket.socket, 'ioctl'))
         self.assertTrue(hasattr(socket, 'SIO_RCVALL'))
         self.assertTrue(hasattr(socket, 'RCVALL_ON'))
         self.assertTrue(hasattr(socket, 'RCVALL_OFF'))
         self.assertTrue(hasattr(socket, 'SIO_KEEPALIVE_VALS'))
         s = socket.socket()
+        self.addCleanup(s.close)
         self.assertRaises(ValueError, s.ioctl, -1, None)
         s.ioctl(socket.SIO_KEEPALIVE_VALS, (1, 100, 100))