diff --git a/src/helper.cpp b/src/helper.cpp
index 4e20ff4..47057ad 100644
--- a/src/helper.cpp
+++ b/src/helper.cpp
@@ -272,7 +272,7 @@ void printTimestamp(Print* _logOutput, int _logLevel) {
 
 BatteryVoltage::BatteryVoltage() {
 #if defined(ESP8266)
-  pinMode(PIN_A0, INPUT);
+  pinMode(PIN_VOLT, INPUT);
 #else
   pinMode(PIN_VOLT, INPUT_PULLDOWN);
 #endif