diff --git a/operame.ino b/operame.ino
index 8ccca6f..fc4833f 100644
--- a/operame.ino
+++ b/operame.ino
@@ -363,6 +363,7 @@ void loop() {
         mqtt_interval,
         [] {
             if (!mqtt_enabled) return;
+            if (co2 <= 0) return;
             connect_mqtt();
             String message = mqtt_template;
             message.replace("{}", String(co2));