diff --git a/pymongo/periodic_executor.py b/pymongo/periodic_executor.py
index f087dd386..07f383724 100644
--- a/pymongo/periodic_executor.py
+++ b/pymongo/periodic_executor.py
@@ -116,7 +116,10 @@ class PeriodicExecutor(object):
                     self._stopped = True
                     break
             except:
-                self._stopped = True
+                with self._lock:
+                    self._stopped = True
+                    self._thread_will_exit = True
+
                 raise
 
             deadline = _time() + self._interval
diff --git a/pymongo/topology.py b/pymongo/topology.py
index cfc6c9958..deb7b7008 100644
--- a/pymongo/topology.py
+++ b/pymongo/topology.py
@@ -350,6 +350,8 @@ class Topology(object):
             # Mark all servers Unknown.
             self._description = self._description.reset()
             self._update_servers()
+            self._opened = False
+
         # Publish only after releasing the lock.
         if self._publish_tp:
             self._events.put((self._listeners.publish_topology_closed,
diff --git a/test/test_threads.py b/test/test_threads.py
index 4f26aad66..f9e17f3a4 100644
--- a/test/test_threads.py
+++ b/test/test_threads.py
@@ -21,7 +21,7 @@ from test import (client_context,
                   db_pwd,
                   IntegrationTest,
                   unittest)
-from test.utils import rs_or_single_client_noauth
+from test.utils import rs_or_single_client_noauth, rs_or_single_client
 from test.utils import frequent_thread_switches, joinall
 from pymongo.errors import OperationFailure
 
@@ -183,25 +183,22 @@ class TestThreads(IntegrationTest):
         error.join()
         okay.join()
 
-    @unittest.skip("PYTHON-1204")
     def test_client_disconnect(self):
-        self.db.drop_collection("test")
-        self.db.test.insert_many([{"x": i} for i in range(1000)])
+        db = rs_or_single_client(serverSelectionTimeoutMS=30000).pymongo_test
+        db.drop_collection("test")
+        db.test.insert_many([{"x": i} for i in range(1000)])
 
         # Start 10 threads that execute a query, and 10 threads that call
         # client.close() 10 times in a row.
-        threads = [SaveAndFind(self.db.test) for _ in range(10)]
-        threads.extend(Disconnect(self.db.client, 10) for _ in range(10))
+        threads = [SaveAndFind(db.test) for _ in range(10)]
+        threads.extend(Disconnect(db.client, 10) for _ in range(10))
 
         with frequent_thread_switches():
-            # Frequent thread switches hurt performance badly enough to
-            # prevent reconnection within 5 seconds, especially in Python 2
-            # on a Windows build slave.
             for t in threads:
                 t.start()
 
             for t in threads:
-                t.join(30)
+                t.join(300)
 
             for t in threads:
                 self.assertTrue(t.passed)