diff --git a/src/handler/mhz19_co2.py b/src/handler/mhz19_co2.py
index 5240780..925308b 100644
--- a/src/handler/mhz19_co2.py
+++ b/src/handler/mhz19_co2.py
@@ -13,9 +13,9 @@ class Mhz19Co2:
         return self.last_read
 
     def read(self) -> int | None:
-        data: dict | None = mh_z19.read()
+        data = mh_z19.read()
 
-        if not data or "co2" not in data.keys():
+        if not data:
             return None
 
         self.last_read = data["co2"]