diff --git a/satella/coding/concurrent/monitor.py b/satella/coding/concurrent/monitor.py
index c889b39143b039539103106c757142dbf7713cee..85fcafad301ac159f1d2b2968c52bbfc2cf8df1c 100644
--- a/satella/coding/concurrent/monitor.py
+++ b/satella/coding/concurrent/monitor.py
@@ -248,7 +248,7 @@ class MonitorSet(set, Monitor):
         :param item: item to insert
         :return: whether the item was successfully inserted
         """
-        with Monitor.synchronize_on(self):
+        with Monitor.acquire(self):
             if item in self:
                 return False
             self.add(item)