diff --git a/sensors.py b/sensors.py
index 43a22c5..e70ef97 100644
--- a/sensors.py
+++ b/sensors.py
@@ -41,7 +41,7 @@ class Temperature1W(Sensor):
             return None
         if content[0].strip()[-3:] != "YES":
             print("INVALID CHECKSUM")
-            return None
+            return (time, None)
         return (time, int(re.search("t=([0-9]+)", content[1]).group(1)) / 1000.0)
 
 class Sensors():