diff --git a/homeassistant/components/sensor/history_stats.py b/homeassistant/components/sensor/history_stats.py
index c76d2cefca0..a8d9276edc8 100644
--- a/homeassistant/components/sensor/history_stats.py
+++ b/homeassistant/components/sensor/history_stats.py
@@ -10,6 +10,7 @@ import math
 
 import voluptuous as vol
 
+from homeassistant.core import callback
 from homeassistant.components import history
 import homeassistant.helpers.config_validation as cv
 import homeassistant.util.dt as dt_util
@@ -19,7 +20,7 @@ from homeassistant.const import (
     EVENT_HOMEASSISTANT_START)
 from homeassistant.exceptions import TemplateError
 from homeassistant.helpers.entity import Entity
-from homeassistant.helpers.event import track_state_change
+from homeassistant.helpers.event import async_track_state_change
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -94,8 +95,6 @@ class HistoryStatsSensor(Entity):
             self, hass, entity_id, entity_state, start, end, duration,
             sensor_type, name):
         """Initialize the HistoryStats sensor."""
-        self._hass = hass
-
         self._entity_id = entity_id
         self._entity_state = entity_state
         self._duration = duration
@@ -109,15 +108,19 @@ class HistoryStatsSensor(Entity):
         self.value = None
         self.count = None
 
-        def force_refresh(*args):
-            """Force the component to refresh."""
-            self.schedule_update_ha_state(True)
+        @callback
+        def start_refresh(*args):
+            """Register state tracking."""
+            @callback
+            def force_refresh(*args):
+                """Force the component to refresh."""
+                self.async_schedule_update_ha_state(True)
 
-        # Update value when home assistant starts
-        hass.bus.listen_once(EVENT_HOMEASSISTANT_START, force_refresh)
+            force_refresh()
+            async_track_state_change(self.hass, self._entity_id, force_refresh)
 
-        # Update value when tracked entity changes its state
-        track_state_change(hass, entity_id, force_refresh)
+        # Delay first refresh to keep startup fast
+        hass.bus.listen_once(EVENT_HOMEASSISTANT_START, start_refresh)
 
     @property
     def name(self):