diff --git a/Marlin/src/HAL/LPC1768/HAL.h b/Marlin/src/HAL/LPC1768/HAL.h
index 2d385fd16c..7d2b289f35 100644
--- a/Marlin/src/HAL/LPC1768/HAL.h
+++ b/Marlin/src/HAL/LPC1768/HAL.h
@@ -49,7 +49,7 @@ extern "C" volatile uint32_t _millis;
 #include <CDCSerial.h>
 
 // i2c uses 8-bit shifted address
-#define I2C_ADDRESS(A) ((A) << 1)
+#define I2C_ADDRESS(A) uint8_t((A) << 1)
 
 //
 // Default graphical display delays
diff --git a/buildroot/share/tests/LPC1769-tests b/buildroot/share/tests/LPC1769-tests
index 53a7b28189..9c7a1ba10e 100755
--- a/buildroot/share/tests/LPC1769-tests
+++ b/buildroot/share/tests/LPC1769-tests
@@ -49,7 +49,8 @@ opt_set Y_DRIVER_TYPE TMC2130
 opt_set Z_DRIVER_TYPE TMC2130
 opt_enable AUTO_BED_LEVELING_BILINEAR EEPROM_SETTINGS EEPROM_CHITCHAT \
            TMC_USE_SW_SPI MONITOR_DRIVER_STATUS STEALTHCHOP_XY STEALTHCHOP_Z HYBRID_THRESHOLD \
-           SENSORLESS_PROBING Z_SAFE_HOMING X_STALL_SENSITIVITY Y_STALL_SENSITIVITY Z_STALL_SENSITIVITY TMC_DEBUG
+           SENSORLESS_PROBING Z_SAFE_HOMING X_STALL_SENSITIVITY Y_STALL_SENSITIVITY Z_STALL_SENSITIVITY TMC_DEBUG \
+           EXPERIMENTAL_I2CBUS
 opt_disable PSU_CONTROL
 exec_test $1 $2 "Cohesion3D Remix DELTA + ABL Bilinear + EEPROM + SENSORLESS_PROBING"