diff --git a/config/examples/Opulo/Lumen_REV3/Configuration.h b/config/examples/Opulo/Lumen_REV3/Configuration.h
index 8f9e34c6f6..ae7d168bf9 100644
--- a/config/examples/Opulo/Lumen_REV3/Configuration.h
+++ b/config/examples/Opulo/Lumen_REV3/Configuration.h
@@ -117,9 +117,9 @@
  * Select a serial port to communicate with RS485 protocol
  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
  */
-//#define RS485_SERIAL_PORT 1
+#define RS485_SERIAL_PORT 1
 #ifdef RS485_SERIAL_PORT
-  //#define RS485_BUS_BUFFER_SIZE 128
+  #define RS485_BUS_BUFFER_SIZE 128
 #endif
 
 // Enable the Bluetooth serial interface on AT90USB devices
diff --git a/config/examples/Opulo/Lumen_REV3/Configuration_adv.h b/config/examples/Opulo/Lumen_REV3/Configuration_adv.h
index 27d2205008..1b05a9cd08 100644
--- a/config/examples/Opulo/Lumen_REV3/Configuration_adv.h
+++ b/config/examples/Opulo/Lumen_REV3/Configuration_adv.h
@@ -3396,7 +3396,7 @@
  * echo:i2c-reply: from:99 bytes:5 data:hello
  */
 
-//#define EXPERIMENTAL_I2CBUS
+#define EXPERIMENTAL_I2CBUS
 #if ENABLED(EXPERIMENTAL_I2CBUS)
   #define I2C_SLAVE_ADDRESS  0  // Set a value from 8 to 127 to act as a slave
 #endif
diff --git a/config/examples/Opulo/Lumen_REV4/Configuration.h b/config/examples/Opulo/Lumen_REV4/Configuration.h
index 347fcebe0d..138d1a9b5f 100644
--- a/config/examples/Opulo/Lumen_REV4/Configuration.h
+++ b/config/examples/Opulo/Lumen_REV4/Configuration.h
@@ -117,9 +117,9 @@
  * Select a serial port to communicate with RS485 protocol
  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
  */
-//#define RS485_SERIAL_PORT 1
+#define RS485_SERIAL_PORT 1
 #ifdef RS485_SERIAL_PORT
-  //#define RS485_BUS_BUFFER_SIZE 128
+  #define RS485_BUS_BUFFER_SIZE 128
 #endif
 
 // Enable the Bluetooth serial interface on AT90USB devices