diff --git a/pymongo/monitor.py b/pymongo/monitor.py
index e26f93b5a..a0e689455 100644
--- a/pymongo/monitor.py
+++ b/pymongo/monitor.py
@@ -120,8 +120,10 @@ class Monitor(object):
 
         start = _time()
         try:
+            cluster_time = self._topology.max_cluster_time()
             # If the server type is unknown, send metadata with first check.
-            return self._check_once(metadata=metadata)
+            return self._check_once(metadata=metadata,
+                                    cluster_time=cluster_time)
         except ReferenceError:
             raise
         except Exception as error:
@@ -137,9 +139,12 @@ class Monitor(object):
                 return default
 
             # Try a second and final time. If it fails return original error.
+            # Always send metadata: this is a new connection.
             start = _time()
             try:
-                return self._check_once(metadata=self._pool.opts.metadata)
+                cluster_time = self._topology.max_cluster_time()
+                return self._check_once(metadata=self._pool.opts.metadata,
+                                        cluster_time=cluster_time)
             except ReferenceError:
                 raise
             except Exception as error:
@@ -150,7 +155,7 @@ class Monitor(object):
                 self._avg_round_trip_time.reset()
                 return default
 
-    def _check_once(self, metadata=None):
+    def _check_once(self, metadata=None, cluster_time=None):
         """A single attempt to call ismaster.
 
         Returns a ServerDescription, or raises an exception.
@@ -160,7 +165,7 @@ class Monitor(object):
             self._listeners.publish_server_heartbeat_started(address)
         with self._pool.get_socket({}) as sock_info:
             response, round_trip_time = self._check_with_socket(
-                sock_info, metadata=metadata)
+                sock_info, metadata=metadata, cluster_time=cluster_time)
             self._avg_round_trip_time.add_sample(round_trip_time)
             sd = ServerDescription(
                 address=address,
@@ -172,7 +177,7 @@ class Monitor(object):
 
             return sd
 
-    def _check_with_socket(self, sock_info, metadata=None):
+    def _check_with_socket(self, sock_info, metadata=None, cluster_time=None):
         """Return (IsMaster, round_trip_time).
 
         Can raise ConnectionFailure or OperationFailure.
@@ -180,6 +185,8 @@ class Monitor(object):
         cmd = SON([('ismaster', 1)])
         if metadata is not None:
             cmd['client'] = metadata
+        if cluster_time is not None:
+            cmd['$clusterTime'] = cluster_time
         start = _time()
         request_id, msg, max_doc_size = message.query(
             0, 'admin.$cmd', 0, -1, cmd,
diff --git a/test/pymongo_mocks.py b/test/pymongo_mocks.py
index b01afcdb5..0ec64109b 100644
--- a/test/pymongo_mocks.py
+++ b/test/pymongo_mocks.py
@@ -76,7 +76,7 @@ class MockMonitor(Monitor):
             pool,
             topology_settings)
 
-    def _check_once(self, metadata=None):
+    def _check_once(self, metadata=None, cluster_time=None):
         address = self._server_description.address
         response, rtt = self.client.mock_is_master('%s:%d' % address)
         return ServerDescription(address, IsMaster(response), rtt)
diff --git a/test/test_heartbeat_monitoring.py b/test/test_heartbeat_monitoring.py
index 5a9d5bb89..53c54abae 100644
--- a/test/test_heartbeat_monitoring.py
+++ b/test/test_heartbeat_monitoring.py
@@ -75,7 +75,7 @@ class TestHeartbeatMonitoring(unittest.TestCase):
                           min_heartbeat_interval=0.1,
                           events_queue_frequency=0.1):
             class MockMonitor(Monitor):
-                def _check_with_socket(self, sock_info, metadata=None):
+                def _check_with_socket(self, *args, **kwargs):
                     if isinstance(responses[1], Exception):
                         raise responses[1]
                     return IsMaster(responses[1]), 99
diff --git a/test/test_topology.py b/test/test_topology.py
index f9328dfa4..4dd19a8ea 100644
--- a/test/test_topology.py
+++ b/test/test_topology.py
@@ -254,7 +254,7 @@ class TestSingleServerTopology(TopologyTest):
         available = True
 
         class TestMonitor(Monitor):
-            def _check_with_socket(self, sock_info, metadata=None):
+            def _check_with_socket(self, *args, **kwargs):
                 if available:
                     return (IsMaster({'ok': 1, 'maxWireVersion': 6}),
                             round_trip_time)
@@ -619,6 +619,7 @@ def wait_for_master(topology):
     thread. In applications this is harmless but it would break some tests,
     so we pass server_selection_timeout=0 and poll instead.
     """
+
     def get_master():
         try:
             return topology.select_server(writable_server_selector, 0)
@@ -636,7 +637,7 @@ class TestTopologyErrors(TopologyTest):
         ismaster_count = [0]
 
         class TestMonitor(Monitor):
-            def _check_with_socket(self, sock_info, metadata=None):
+            def _check_with_socket(self, *args, **kwargs):
                 ismaster_count[0] += 1
                 if ismaster_count[0] == 1:
                     return IsMaster({'ok': 1, 'maxWireVersion': 6}), 0
@@ -657,7 +658,7 @@ class TestTopologyErrors(TopologyTest):
         ismaster_count = [0]
 
         class TestMonitor(Monitor):
-            def _check_with_socket(self, sock_info, metadata=None):
+            def _check_with_socket(self, *args, **kwargs):
                 ismaster_count[0] += 1
                 if ismaster_count[0] in (1, 3):
                     return IsMaster({'ok': 1, 'maxWireVersion': 6}), 0
@@ -679,7 +680,7 @@ class TestTopologyErrors(TopologyTest):
         exception = AssertionError('internal error')
 
         class TestMonitor(Monitor):
-            def _check_with_socket(self, sock_info, metadata=None):
+            def _check_with_socket(self, *args, **kwargs):
                 raise exception
 
         t = create_mock_topology(monitor_class=TestMonitor)