diff --git a/adafruit_tca9548a.py b/adafruit_tca9548a.py
index dc3d7a1..c42ae73 100644
--- a/adafruit_tca9548a.py
+++ b/adafruit_tca9548a.py
@@ -67,6 +67,7 @@ def try_lock(self):
 
     def unlock(self):
         """Pass thru for unlock."""
+        self.tca.i2c.writeto(self.tca.address, b'\x00')
         return self.tca.i2c.unlock()
 
     def readfrom_into(self, address, buffer, **kwargs):