diff --git a/eventlet/coros.py b/eventlet/coros.py
index aeaf0bc..2b6fed8 100644
--- a/eventlet/coros.py
+++ b/eventlet/coros.py
@@ -508,8 +508,8 @@ class Channel(object):
             if self._waiters:
                 api.get_hub().schedule_call_global(0, self._do_switch)
         else:
-#             if self._waiters and self._senders:
-#                 api.sleep(0)
+            if self._waiters and self._senders:
+                api.sleep(0)
             self.items.append((result, exc))
             # note that send() does not work well with timeouts. if your timeout fires
             # after this point, the item will remain in the queue