diff --git a/custom_components/nws_alerts/sensor.py b/custom_components/nws_alerts/sensor.py
index 6612d6f..303bfac 100644
--- a/custom_components/nws_alerts/sensor.py
+++ b/custom_components/nws_alerts/sensor.py
@@ -1,8 +1,9 @@
-import requests
+import aiohttp
 import logging
 import voluptuous as vol
 from datetime import timedelta
-from homeassistant.const import CONF_NAME, ATTR_ATTRIBUTION
+from homeassistant.core import callback
+from homeassistant.const import CONF_NAME, ATTR_ATTRIBUTION, EVENT_HOMEASSISTANT_START
 from homeassistant.helpers.entity import Entity
 from homeassistant.util import Throttle
 from homeassistant.components.sensor import PLATFORM_SCHEMA
@@ -61,7 +62,6 @@ def __init__(self, name, zone_id):
         self._display_desc = None
         self._spoken_desc = None
         self._zone_id = zone_id.replace(' ', '')
-        self.update()
 
     @property
     def unique_id(self):
@@ -98,19 +98,33 @@ def device_state_attributes(self):
 
         return attrs
 
+    async def async_added_to_hass(self):
+        """Register callbacks."""
+        _LOGGER.debug("Registering: %s...", self.entity_id)
+
+        @callback
+        def sensor_startup(event):        
+            """Update sensor on startup."""
+
+            self.async_schedule_update_ha_state(True)
+
+        self.hass.bus.async_listen_once(
+            EVENT_HOMEASSISTANT_START, sensor_startup
+        )        
+
     @Throttle(MIN_TIME_BETWEEN_UPDATES)
-    def update(self):
+    async def async_update(self):
         """Fetch new state data for the sensor.
         This is the only method that should fetch new data for Home Assistant.
         """
-        values = self.get_state()
+        values = await self.async_get_state()
         self._state = values['state']
         self._event = values['event']
         self._event_id = values['event_id']
         self._display_desc = values['display_desc']
         self._spoken_desc = values['spoken_desc']
 
-    def get_state(self):
+    async def async_get_state(self):
         values = {'state': 0,
                   'event': None,
                   'event_id': None,
@@ -122,19 +136,24 @@ def get_state(self):
                    'Accept': 'application/ld+json'
                    }
 
+        data = None
         url = '%s/alerts/active/count' % API_ENDPOINT
-        r = requests.get(url, headers=headers)
-        _LOGGER.debug("getting state for %s from %s" % (self._zone_id, url))
-        if r.status_code == 200:
-            if 'zones' in r.json():
+        async with aiohttp.ClientSession() as session:
+            async with session.get(url, headers=headers) as r:
+                _LOGGER.debug("getting state for %s from %s" % (self._zone_id, url))
+                if r.status == 200:
+                    data = await r.json()
+        
+        if data is not None:
+            if 'zones' in data:
                 for zone in self._zone_id.split(','):
-                    if zone in r.json()['zones']:
-                        values = self.get_alerts()
+                    if zone in data['zones']:
+                        values = await self.async_get_alerts()
                         break
 
         return values
 
-    def get_alerts(self):
+    async def async_get_alerts(self):
         values = {'state': 0,
                   'event': None,
                   'event_id': None,
@@ -145,16 +164,21 @@ def get_alerts(self):
         headers = {'User-Agent': USER_AGENT,
                    'Accept': 'application/geo+json'
                    }
+        data = None
         url = '%s/alerts/active?zone=%s' % (API_ENDPOINT, self._zone_id)
-        r = requests.get(url, headers=headers)
-        _LOGGER.debug("getting alert for %s from %s" % (self._zone_id, url))
-        if r.status_code == 200:
+        async with aiohttp.ClientSession() as session:
+            async with session.get(url, headers=headers) as r:
+                _LOGGER.debug("getting alert for %s from %s" % (self._zone_id, url))
+                if r.status == 200:
+                    data = await r.json()
+
+        if data is not None:
             events = []
             headlines = []
             event_id = ''
             display_desc = ''
             spoken_desc = ''
-            features = r.json()['features']
+            features = data['features']
             for alert in features:
                 event = alert['properties']['event']
                 if 'NWSheadline' in alert['properties']['parameters']:
@@ -208,7 +232,7 @@ def get_alerts(self):
                 values['display_desc'] = display_desc
                 values['spoken_desc'] = spoken_desc
                 
-        if r.status_code != 200:
+        if data is None:
                 values['state'] = "Unknown"
                 values['event'] = "Unknown"
                 values['event_id'] = "Unknown"