diff --git a/watcher/common/nova_helper.py b/watcher/common/nova_helper.py
index 55a1aff94..c4b0e7399 100644
--- a/watcher/common/nova_helper.py
+++ b/watcher/common/nova_helper.py
@@ -478,6 +478,9 @@ class NovaHelper(object):
                           'OS-EXT-SRV-ATTR:host') != dest_hostname \
                     and retry:
                 instance = self.nova.servers.get(instance.id)
+                if not getattr(instance, 'OS-EXT-STS:task_state'):
+                    LOG.debug("Instance task state: %s is null" % instance_id)
+                    break
                 LOG.debug(
                     'Waiting the migration of {0}  to {1}'.format(
                         instance,
diff --git a/watcher/tests/common/test_nova_helper.py b/watcher/tests/common/test_nova_helper.py
index a554b502c..778b569ee 100644
--- a/watcher/tests/common/test_nova_helper.py
+++ b/watcher/tests/common/test_nova_helper.py
@@ -165,6 +165,27 @@ class TestNovaHelper(base.TestCase):
         )
         self.assertFalse(is_success)
 
+    @mock.patch.object(time, 'sleep', mock.Mock())
+    def test_live_migrate_instance_with_task_state(
+            self, mock_glance, mock_cinder, mock_neutron, mock_nova):
+        nova_util = nova_helper.NovaHelper()
+        server = self.fake_server(self.instance_uuid)
+        setattr(server, 'OS-EXT-SRV-ATTR:host',
+                        self.source_node)
+        setattr(server, 'OS-EXT-STS:task_state', '')
+        self.fake_nova_find_list(nova_util, find=server, list=None)
+        nova_util.live_migrate_instance(
+            self.instance_uuid, self.destination_node
+        )
+        time.sleep.assert_not_called()
+
+        setattr(server, 'OS-EXT-STS:task_state', 'migrating')
+        self.fake_nova_find_list(nova_util, find=server, list=server)
+        nova_util.live_migrate_instance(
+            self.instance_uuid, self.destination_node
+        )
+        time.sleep.assert_called_with(1)
+
     @mock.patch.object(time, 'sleep', mock.Mock())
     def test_live_migrate_instance_no_destination_node(
             self, mock_glance, mock_cinder, mock_neutron, mock_nova):