diff --git a/ampel-firmware/co2_sensor.cpp b/ampel-firmware/co2_sensor.cpp
index 400416a602d353cdebc09f3d183a516c9624b565..d726d28319c889cfceb8137ed3aeefde3830424e 100644
--- a/ampel-firmware/co2_sensor.cpp
+++ b/ampel-firmware/co2_sensor.cpp
@@ -4,7 +4,6 @@
 #include "ntp.h"
 #include "led_effects.h"
 #include "sensor_console.h"
-#include <Wire.h>
 
 #include "src/lib/S8_UART/s8_uart.h"
 
@@ -18,7 +17,15 @@ namespace config {
   const bool debug_sensor_states = false; // If true, log state transitions over serial console
 }
 
+#if defined(ESP8266)
+    // ???
+#endif
+#if defined(ESP32)
+// For ESP32 : RX on GPIO17, TX on GPIO16
+#   define S8_UART_PORT  2
+
 namespace sensor {
+  HardwareSerial S8_serial(S8_UART_PORT);
   S8_UART *sensor_S8;
   S8_sensor s8;
   uint16_t co2 = 0;
@@ -57,13 +64,6 @@ namespace sensor {
   void setAutoCalibration(int32_t autoCalibration);
 
   void initialize() {
-#if defined(ESP8266)
-    Wire.begin(12, 14); // ESP8266 - D6, D5;
-#endif
-#if defined(ESP32)
-    // For ESP32 : RX on GPIO17, TX on GPIO16
-#   define S8_UART_PORT  2
-    HardwareSerial S8_serial(S8_UART_PORT);
     S8_serial.begin(S8_BAUDRATE);
     sensor_S8 = new S8_UART(S8_serial);
 #endif