diff --git a/companion/src/firmwares/opentx/opentxeeprom.cpp b/companion/src/firmwares/opentx/opentxeeprom.cpp
index 8e0c408db..ca698adc0 100644
--- a/companion/src/firmwares/opentx/opentxeeprom.cpp
+++ b/companion/src/firmwares/opentx/opentxeeprom.cpp
@@ -1918,7 +1918,7 @@ class SensorField: public TransformedField {
       if (sensor.type == SensorData::TELEM_TYPE_CUSTOM) {
         _id = sensor.id;
         _subid = sensor.subid;
-        _instance = ((sensor.instance - 1) & 0x1F) | (sensor.rxIdx << 5) | (sensor.moduleIdx << 7);
+        _instance = sensor.instance == 0 ? 0 : ((sensor.instance - 1) & 0x1F) | (sensor.rxIdx << 5) | (sensor.moduleIdx << 7);
         _ratio = sensor.ratio;
         _offset = sensor.offset;
       }