diff --git a/homeassistant/components/unifi/device_tracker.py b/homeassistant/components/unifi/device_tracker.py
index 5cfb8624116..8c4e54e0129 100644
--- a/homeassistant/components/unifi/device_tracker.py
+++ b/homeassistant/components/unifi/device_tracker.py
@@ -6,12 +6,13 @@ import voluptuous as vol
 
 from homeassistant import config_entries
 from homeassistant.components import unifi
-from homeassistant.components.device_tracker import PLATFORM_SCHEMA
+from homeassistant.components.device_tracker import DOMAIN, PLATFORM_SCHEMA
 from homeassistant.components.device_tracker.config_entry import ScannerEntity
 from homeassistant.components.device_tracker.const import SOURCE_TYPE_ROUTER
 from homeassistant.core import callback
 from homeassistant.const import (
     CONF_HOST, CONF_USERNAME, CONF_PASSWORD, CONF_PORT, CONF_VERIFY_SSL)
+from homeassistant.helpers import entity_registry
 from homeassistant.helpers.device_registry import CONNECTION_NETWORK_MAC
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
 
@@ -80,6 +81,23 @@ async def async_setup_entry(hass, config_entry, async_add_entities):
     controller = hass.data[unifi.DOMAIN][controller_id]
     tracked = {}
 
+    registry = await entity_registry.async_get_registry(hass)
+
+    # Restore clients that is not a part of active clients list.
+    for entity in registry.entities.values():
+
+        if entity.config_entry_id == config_entry.entry_id and \
+                entity.domain == DOMAIN:
+
+            mac, _ = entity.unique_id.split('-', 1)
+
+            if mac in controller.api.clients or \
+                    mac not in controller.api.clients_all:
+                continue
+
+            client = controller.api.clients_all[mac]
+            controller.api.clients.process_raw([client.raw])
+
     @callback
     def update_controller():
         """Update the values of the controller."""
diff --git a/tests/components/unifi/test_device_tracker.py b/tests/components/unifi/test_device_tracker.py
index 3a209e610ce..f8be08975fa 100644
--- a/tests/components/unifi/test_device_tracker.py
+++ b/tests/components/unifi/test_device_tracker.py
@@ -6,7 +6,7 @@ from datetime import timedelta
 
 import pytest
 
-from aiounifi.clients import Clients
+from aiounifi.clients import Clients, ClientsAll
 from aiounifi.devices import Devices
 
 from homeassistant import config_entries
@@ -15,6 +15,7 @@ from homeassistant.components.unifi.const import (
     CONF_CONTROLLER, CONF_SITE_ID, UNIFI_CONFIG)
 from homeassistant.const import (
     CONF_HOST, CONF_PASSWORD, CONF_PORT, CONF_USERNAME, CONF_VERIFY_SSL)
+from homeassistant.helpers import entity_registry
 from homeassistant.setup import async_setup_component
 
 import homeassistant.components.device_tracker as device_tracker
@@ -75,6 +76,7 @@ def mock_controller(hass):
 
     controller.mock_client_responses = deque()
     controller.mock_device_responses = deque()
+    controller.mock_client_all_responses = deque()
 
     async def mock_request(method, path, **kwargs):
         kwargs['method'] = method
@@ -84,10 +86,13 @@ def mock_controller(hass):
             return controller.mock_client_responses.popleft()
         if path == 's/{site}/stat/device':
             return controller.mock_device_responses.popleft()
+        if path == 's/{site}/rest/user':
+            return controller.mock_client_all_responses.popleft()
         return None
 
     controller.api.clients = Clients({}, mock_request)
     controller.api.devices = Devices({}, mock_request)
+    controller.api.clients_all = ClientsAll({}, mock_request)
 
     return controller
 
@@ -98,7 +103,7 @@ async def setup_controller(hass, mock_controller):
     hass.data[unifi.DOMAIN] = {CONTROLLER_ID: mock_controller}
     config_entry = config_entries.ConfigEntry(
         1, unifi.DOMAIN, 'Mock Title', ENTRY_CONFIG, 'test',
-        config_entries.CONN_CLASS_LOCAL_POLL)
+        config_entries.CONN_CLASS_LOCAL_POLL, entry_id=1)
     mock_controller.config_entry = config_entry
 
     await mock_controller.async_update()
@@ -159,3 +164,30 @@ async def test_tracked_devices(hass, mock_controller):
 
     device_1 = hass.states.get('device_tracker.client_1')
     assert device_1.state == 'home'
+
+
+async def test_restoring_client(hass, mock_controller):
+    """Test the update_items function with some clients."""
+    mock_controller.mock_client_responses.append([CLIENT_2])
+    mock_controller.mock_device_responses.append({})
+    mock_controller.mock_client_all_responses.append([CLIENT_1])
+    mock_controller.unifi_config = {
+        unifi.CONF_BLOCK_CLIENT: True
+    }
+
+    registry = await entity_registry.async_get_registry(hass)
+    registry.async_get_or_create(
+        device_tracker.DOMAIN, unifi_dt.UNIFI_DOMAIN,
+        '{}-mock-site'.format(CLIENT_1['mac']),
+        suggested_object_id=CLIENT_1['hostname'], config_entry_id=1)
+    registry.async_get_or_create(
+        device_tracker.DOMAIN, unifi_dt.UNIFI_DOMAIN,
+        '{}-mock-site'.format(CLIENT_2['mac']),
+        suggested_object_id=CLIENT_2['hostname'], config_entry_id=1)
+
+    await setup_controller(hass, mock_controller)
+    assert len(mock_controller.mock_requests) == 3
+    assert len(hass.states.async_all()) == 4
+
+    device_1 = hass.states.get('device_tracker.client_1')
+    assert device_1 is not None