diff --git a/homeassistant/components/mysensors/__init__.py b/homeassistant/components/mysensors/__init__.py
index a2ba4eaf176..84f2e788c53 100644
--- a/homeassistant/components/mysensors/__init__.py
+++ b/homeassistant/components/mysensors/__init__.py
@@ -173,9 +173,12 @@ async def async_setup_entry(hass: HomeAssistantType, entry: ConfigEntry) -> bool
         _LOGGER.error("gateway setup failed")
         return False
 
-    if MYSENSORS_GATEWAYS not in hass.data:
-        hass.data[MYSENSORS_GATEWAYS] = {}
-    hass.data[MYSENSORS_GATEWAYS][entry.entry_id] = gateway
+    if DOMAIN not in hass.data:
+        hass.data[DOMAIN] = {}
+
+    if MYSENSORS_GATEWAYS not in hass.data[DOMAIN]:
+        hass.data[DOMAIN][MYSENSORS_GATEWAYS] = {}
+    hass.data[DOMAIN][MYSENSORS_GATEWAYS][entry.entry_id] = gateway
 
     async def finish():
         for platform in SUPPORTED_PLATFORMS_WITH_ENTRY_SUPPORT:
@@ -200,11 +203,11 @@ async def async_unload_entry(hass: HomeAssistantType, entry: ConfigEntry) -> boo
         await hass.config_entries.async_forward_entry_unload(entry, platform)
 
     key = MYSENSORS_ON_UNLOAD.format(entry.entry_id)
-    if key in hass.data:
-        for fnct in hass.data[key]:
+    if key in hass.data[DOMAIN]:
+        for fnct in hass.data[DOMAIN][key]:
             fnct()
 
-    del hass.data[MYSENSORS_GATEWAYS][entry.entry_id]
+    del hass.data[DOMAIN][MYSENSORS_GATEWAYS][entry.entry_id]
 
     hass.async_create_task(gw_stop(hass, gateway))
     return True
@@ -222,9 +225,9 @@ async def on_unload(
     else:
         uniqueid = entry.entry_id
     key = MYSENSORS_ON_UNLOAD.format(uniqueid)
-    if key not in hass.data:
-        hass.data[key] = []
-    hass.data[key].append(fnct)
+    if key not in hass.data[DOMAIN]:
+        hass.data[DOMAIN][key] = []
+    hass.data[DOMAIN][key].append(fnct)
 
 
 @callback
diff --git a/homeassistant/components/mysensors/device.py b/homeassistant/components/mysensors/device.py
index 11a395490f0..907612a7996 100644
--- a/homeassistant/components/mysensors/device.py
+++ b/homeassistant/components/mysensors/device.py
@@ -60,8 +60,8 @@ class MySensorsDevice:
         """Remove this entity from home assistant."""
         for platform in PLATFORM_TYPES:
             platform_str = MYSENSORS_PLATFORM_DEVICES.format(platform)
-            if platform_str in self.hass.data:
-                platform_dict = self.hass.data[platform_str]
+            if platform_str in self.hass.data[DOMAIN]:
+                platform_dict = self.hass.data[DOMAIN][platform_str]
                 if self.dev_id in platform_dict:
                     if platform_dict[self.dev_id] is not self:
                         self._logger.warning(
@@ -192,9 +192,9 @@ class MySensorsDevice:
 
 def get_mysensors_devices(hass, domain: str) -> Dict[DevId, MySensorsDevice]:
     """Return MySensors devices for a hass platform name."""
-    if MYSENSORS_PLATFORM_DEVICES.format(domain) not in hass.data:
-        hass.data[MYSENSORS_PLATFORM_DEVICES.format(domain)] = {}
-    return hass.data[MYSENSORS_PLATFORM_DEVICES.format(domain)]
+    if MYSENSORS_PLATFORM_DEVICES.format(domain) not in hass.data[DOMAIN]:
+        hass.data[DOMAIN][MYSENSORS_PLATFORM_DEVICES.format(domain)] = {}
+    return hass.data[DOMAIN][MYSENSORS_PLATFORM_DEVICES.format(domain)]
 
 
 class MySensorsEntity(MySensorsDevice, Entity):
diff --git a/homeassistant/components/mysensors/gateway.py b/homeassistant/components/mysensors/gateway.py
index cccd63622bf..181ba6be7db 100644
--- a/homeassistant/components/mysensors/gateway.py
+++ b/homeassistant/components/mysensors/gateway.py
@@ -25,6 +25,7 @@ from .const import (
     CONF_TOPIC_IN_PREFIX,
     CONF_TOPIC_OUT_PREFIX,
     CONF_VERSION,
+    DOMAIN,
     MYSENSORS_GATEWAY_READY,
     MYSENSORS_GATEWAY_START_TASK,
     MYSENSORS_GATEWAYS,
@@ -62,9 +63,9 @@ def get_mysensors_gateway(
     hass: HomeAssistantType, gateway_id: GatewayId
 ) -> Optional[BaseAsyncGateway]:
     """Return the Gateway for a given GatewayId."""
-    if MYSENSORS_GATEWAYS not in hass.data:
-        hass.data[MYSENSORS_GATEWAYS] = {}
-    gateways = hass.data.get(MYSENSORS_GATEWAYS)
+    if MYSENSORS_GATEWAYS not in hass.data[DOMAIN]:
+        hass.data[DOMAIN][MYSENSORS_GATEWAYS] = {}
+    gateways = hass.data[DOMAIN].get(MYSENSORS_GATEWAYS)
     return gateways.get(gateway_id)
 
 
@@ -217,7 +218,7 @@ async def _discover_persistent_devices(
 async def gw_stop(hass, gateway: BaseAsyncGateway):
     """Stop the gateway."""
     _LOGGER.info("stopping gateway %s", gateway.entry_id)
-    connect_task = hass.data.get(
+    connect_task = hass.data[DOMAIN].get(
         MYSENSORS_GATEWAY_START_TASK.format(gateway.entry_id), None
     )
     if connect_task is not None and not connect_task.done():
@@ -228,7 +229,7 @@ async def gw_stop(hass, gateway: BaseAsyncGateway):
 async def _gw_start(hass: HomeAssistantType, gateway: BaseAsyncGateway):
     """Start the gateway."""
     # Don't use hass.async_create_task to avoid holding up setup indefinitely.
-    hass.data[
+    hass.data[DOMAIN][
         MYSENSORS_GATEWAY_START_TASK.format(gateway.entry_id)
     ] = asyncio.create_task(
         gateway.start()
@@ -243,7 +244,7 @@ async def _gw_start(hass: HomeAssistantType, gateway: BaseAsyncGateway):
         return
     gateway_ready = asyncio.Future()
     gateway_ready_key = MYSENSORS_GATEWAY_READY.format(gateway.entry_id)
-    hass.data[gateway_ready_key] = gateway_ready
+    hass.data[DOMAIN][gateway_ready_key] = gateway_ready
 
     try:
         with async_timeout.timeout(GATEWAY_READY_TIMEOUT):
@@ -255,7 +256,7 @@ async def _gw_start(hass: HomeAssistantType, gateway: BaseAsyncGateway):
             GATEWAY_READY_TIMEOUT,
         )
     finally:
-        hass.data.pop(gateway_ready_key, None)
+        hass.data[DOMAIN].pop(gateway_ready_key, None)
 
 
 def _gw_callback_factory(