diff --git a/chime/main.py b/chime/main.py
index 249d957..df8a91a 100644
--- a/chime/main.py
+++ b/chime/main.py
@@ -73,7 +73,7 @@ def main(credspath='/etc/chime/creds.dat', logpath='/var/lib/pht.csv'):
         reading = sensor.reading()
         show_temperature(reading)
         write_reading(logfile, reading)
-        publisher.publish(reading.json())
+        publisher.publish(reading.json(), b"pht")
         db.store(reading)
         sleep(120)