diff --git a/src/sys/gpio/hasp_gpio.cpp b/src/sys/gpio/hasp_gpio.cpp
index 924e63df..3ae93dc0 100644
--- a/src/sys/gpio/hasp_gpio.cpp
+++ b/src/sys/gpio/hasp_gpio.cpp
@@ -293,7 +293,8 @@ void gpioSetup()
             case HASP_GPIO_SERIAL_DIMMER:
                 const char command[9] = "\xEF\x01\x4D\xA3"; // Start Lanbon Dimmer
 #if defined(ARDUINO_ARCH_ESP32)
-                Serial2.begin(115200, SERIAL_8N1, UART_PIN_NO_CHANGE, gpioConfig[i].pin, 2000);
+                Serial2.begin(115200UL, SERIAL_8N1, UART_PIN_NO_CHANGE, gpioConfig[i].pin, 2000);
+                Serial2.flush();
                 delay(20);
                 Serial2.print("  ");
                 delay(20);