diff --git a/homeassistant/components/cast/media_player.py b/homeassistant/components/cast/media_player.py
index 20a44c0e910..c66f74f74a9 100644
--- a/homeassistant/components/cast/media_player.py
+++ b/homeassistant/components/cast/media_player.py
@@ -323,6 +323,7 @@ class CastDevice(MediaPlayerDevice):
 
     def __init__(self, cast_info):
         """Initialize the cast device."""
+        import pychromecast  # noqa: pylint: disable=unused-import
         self._cast_info = cast_info  # type: ChromecastInfo
         self._chromecast = None  # type: Optional[pychromecast.Chromecast]
         self.cast_status = None
diff --git a/homeassistant/components/device_tracker/bbox.py b/homeassistant/components/device_tracker/bbox.py
index 297e98e548a..f59c922577b 100644
--- a/homeassistant/components/device_tracker/bbox.py
+++ b/homeassistant/components/device_tracker/bbox.py
@@ -45,6 +45,8 @@ class BboxDeviceScanner(DeviceScanner):
 
     def __init__(self, config):
         """Get host from config."""
+        from typing import List  # noqa: pylint: disable=unused-import
+
         self.host = config[CONF_HOST]
 
         """Initialize the scanner."""
diff --git a/homeassistant/components/isy994/__init__.py b/homeassistant/components/isy994/__init__.py
index a9916ed54fe..2b5f8fcb13f 100644
--- a/homeassistant/components/isy994/__init__.py
+++ b/homeassistant/components/isy994/__init__.py
@@ -265,7 +265,7 @@ def _is_sensor_a_binary_sensor(hass: HomeAssistant, node) -> bool:
 
 
 def _categorize_nodes(hass: HomeAssistant, nodes, ignore_identifier: str,
-                      sensor_identifier: str)-> None:
+                      sensor_identifier: str) -> None:
     """Sort the nodes to their proper domains."""
     for (path, node) in nodes:
         ignored = ignore_identifier in path or ignore_identifier in node.name
diff --git a/homeassistant/core.py b/homeassistant/core.py
index 6ddefd2022d..5cd23e9f9a2 100644
--- a/homeassistant/core.py
+++ b/homeassistant/core.py
@@ -778,7 +778,7 @@ class StateMachine:
         self._bus = bus
         self._loop = loop
 
-    def entity_ids(self, domain_filter: Optional[str] = None)-> List[str]:
+    def entity_ids(self, domain_filter: Optional[str] = None) -> List[str]:
         """List of entity ids that are being tracked."""
         future = run_callback_threadsafe(
             self._loop, self.async_entity_ids, domain_filter
@@ -800,13 +800,13 @@ class StateMachine:
         return [state.entity_id for state in self._states.values()
                 if state.domain == domain_filter]
 
-    def all(self)-> List[State]:
+    def all(self) -> List[State]:
         """Create a list of all states."""
         return run_callback_threadsafe(  # type: ignore
             self._loop, self.async_all).result()
 
     @callback
-    def async_all(self)-> List[State]:
+    def async_all(self) -> List[State]:
         """Create a list of all states.
 
         This method must be run in the event loop.
diff --git a/requirements_test.txt b/requirements_test.txt
index af256efc709..d99d878ef63 100644
--- a/requirements_test.txt
+++ b/requirements_test.txt
@@ -4,7 +4,7 @@
 asynctest==0.12.2
 coveralls==1.2.0
 flake8-docstrings==1.3.0
-flake8==3.6.0
+flake8==3.7.5
 mock-open==1.3.1
 mypy==0.650
 pydocstyle==3.0.0
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index 611b20d6a0c..cb6d000dca8 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -5,7 +5,7 @@
 asynctest==0.12.2
 coveralls==1.2.0
 flake8-docstrings==1.3.0
-flake8==3.6.0
+flake8==3.7.5
 mock-open==1.3.1
 mypy==0.650
 pydocstyle==3.0.0
diff --git a/tests/components/sensor/test_dsmr.py b/tests/components/sensor/test_dsmr.py
index 8d9df11116a..dbf1e1fe7dd 100644
--- a/tests/components/sensor/test_dsmr.py
+++ b/tests/components/sensor/test_dsmr.py
@@ -82,7 +82,7 @@ def test_default_setup(hass, mock_connection_factory):
     # ensure entities have new state value after incoming telegram
     power_consumption = hass.states.get('sensor.power_consumption')
     assert power_consumption.state == '0.0'
-    assert power_consumption.attributes.get('unit_of_measurement') is 'kWh'
+    assert power_consumption.attributes.get('unit_of_measurement') == 'kWh'
 
     # tariff should be translated in human readable and have no unit
     power_tariff = hass.states.get('sensor.power_tariff')
diff --git a/tests/components/zwave/test_init.py b/tests/components/zwave/test_init.py
index 85cca89eefc..212d3e02802 100644
--- a/tests/components/zwave/test_init.py
+++ b/tests/components/zwave/test_init.py
@@ -214,7 +214,7 @@ async def test_node_discovery(hass, mock_openzwave):
     hass.async_add_job(mock_receivers[0], node)
     await hass.async_block_till_done()
 
-    assert hass.states.get('zwave.mock_node').state is 'unknown'
+    assert hass.states.get('zwave.mock_node').state == 'unknown'
 
 
 async def test_unparsed_node_discovery(hass, mock_openzwave):
@@ -257,7 +257,7 @@ async def test_unparsed_node_discovery(hass, mock_openzwave):
                 assert len(mock_logger.warning.mock_calls) == 1
                 assert mock_logger.warning.mock_calls[0][1][1:] == \
                     (14, const.NODE_READY_WAIT_SECS)
-    assert hass.states.get('zwave.unknown_node_14').state is 'unknown'
+    assert hass.states.get('zwave.unknown_node_14').state == 'unknown'
 
 
 async def test_node_ignored(hass, mock_openzwave):
@@ -307,7 +307,7 @@ async def test_value_discovery(hass, mock_openzwave):
     await hass.async_block_till_done()
 
     assert hass.states.get(
-        'binary_sensor.mock_node_mock_value').state is 'off'
+        'binary_sensor.mock_node_mock_value').state == 'off'
 
 
 async def test_value_discovery_existing_entity(hass, mock_openzwave):