diff --git a/main.py b/main.py
index 7f5cf5e..610f0d0 100644
--- a/main.py
+++ b/main.py
@@ -19,10 +19,12 @@ except FileNotFoundError:
     logging.error("hosts.json not found. Please copy hosts.json.example to hosts.json and configure it.")
     exit(1)
 
-def alert_tanner(message):
+async def alert_tanner(message):
     try:
         params = {'ssl-monitor': message}
-        requests.get('https://tbot.tannercollin.com/message', params=params, timeout=4)
+        async with aiohttp.ClientSession() as session:
+            async with session.get('https://tbot.tannercollin.com/message', params=params, timeout=4) as response:
+                response.raise_for_status()
     except BaseException as e:
         logging.error('Problem alerting Tanner: ' + str(e))
 
@@ -43,7 +45,7 @@ async def check_host_cert(host, port, seen_serials):
             # this case should be rare if handshake succeeded
             msg = f"Could not get certificate for {host}:{port}"
             logging.warning(msg)
-            alert_tanner(msg)
+            await alert_tanner(msg)
             return
 
         serial_number = cert.get('serialNumber')
@@ -61,18 +63,18 @@ async def check_host_cert(host, port, seen_serials):
         if time_left < timedelta(days=7):
             msg = f"Certificate for {host}:{port} expires in less than a week: {expiry_date}"
             logging.warning(msg)
-            alert_tanner(msg)
+            await alert_tanner(msg)
         else:
             logging.info(f"Certificate for {host}:{port} is valid until {expiry_date} ({time_left.days} days left)")
 
     except ssl.SSLCertVerificationError as e:
         msg = f"Certificate verification error for {host}:{port}: {e.reason}"
         logging.error(msg)
-        alert_tanner(msg)
+        await alert_tanner(msg)
     except ssl.SSLError as e:
         msg = f"SSL error for {host}:{port}: {e}"
         logging.error(msg)
-        alert_tanner(msg)
+        await alert_tanner(msg)
     except (asyncio.TimeoutError, OSError) as e:
         # Per instructions: log and move on for connection errors
         logging.error(f"Connection error for {host}:{port}: {e}")
@@ -80,7 +82,7 @@ async def check_host_cert(host, port, seen_serials):
         # Catchall for other things
         msg = f"An unexpected error occurred for {host}:{port}: {e}"
         logging.error(msg)
-        alert_tanner(msg)
+        await alert_tanner(msg)
 
 
 async def main():