diff --git a/SerialArduino.cpp b/SerialArduino.cpp
index 5aab5e8..af23141 100644
--- a/SerialArduino.cpp
+++ b/SerialArduino.cpp
@@ -37,6 +37,8 @@ void CSerialPort::beginInt(uint8_t n, int speed)
     case 3U:
     #if defined(SERIAL_REPEATER) && defined(__STM32F1__)
       Serial2.begin(speed);
+    #elif defined(SERIAL_REPEATER_USART1) && defined(__STM32F1__)
+      Serial1.begin(speed);
     #elif defined(SERIAL_REPEATER) && (defined(__MK20DX256__) || defined(__MK64FX512__) || defined(__MK66FX1M0__))
       Serial1.begin(speed);
     #endif
@@ -58,6 +60,8 @@ int CSerialPort::availableInt(uint8_t n)
     case 3U:
     #if defined(SERIAL_REPEATER) && defined(__STM32F1__)
       return Serial2.available();
+    #elif defined(SERIAL_REPEATER_USART1) && defined(__STM32F1__)
+      return Serial1.available();
     #elif defined(SERIAL_REPEATER) && (defined(__MK20DX256__) || defined(__MK64FX512__) || defined(__MK66FX1M0__))
       return Serial1.available();
     #endif
@@ -78,6 +82,8 @@ uint8_t CSerialPort::readInt(uint8_t n)
     case 3U:
     #if defined(SERIAL_REPEATER) && defined(__STM32F1__)
       return Serial2.read();
+    #elif defined(SERIAL_REPEATER_USART1) && defined(__STM32F1__)
+      return Serial1.read();
     #elif defined(SERIAL_REPEATER) && (defined(__MK20DX256__) || defined(__MK64FX512__) || defined(__MK66FX1M0__))
       return Serial1.read();
     #endif
@@ -101,6 +107,8 @@ void CSerialPort::writeInt(uint8_t n, const uint8_t* data, uint16_t length, bool
     case 3U:
     #if defined(SERIAL_REPEATER) && defined(__STM32F1__)
       Serial2.write(data, length);
+    #elif defined(SERIAL_REPEATER_USART1) && defined(__STM32F1__)
+      Serial1.write(data, length);
     #elif defined(SERIAL_REPEATER) && (defined(__MK20DX256__) || defined(__MK64FX512__) || defined(__MK66FX1M0__))
       Serial1.write(data, length);
     #endif
diff --git a/SerialPort.cpp b/SerialPort.cpp
index b95210c..b5c0c81 100644
--- a/SerialPort.cpp
+++ b/SerialPort.cpp
@@ -389,7 +389,7 @@ void CSerialPort::start()
 {
   beginInt(1U, 115200);
 
-#if defined(SERIAL_REPEATER)
+#if defined(SERIAL_REPEATER) || defined(SERIAL_REPEATER_USART1)
   beginInt(3U, 9600);
 #endif
 }
@@ -627,7 +627,7 @@ void CSerialPort::process()
             }
             break;
 
-#if defined(SERIAL_REPEATER)
+#if defined(SERIAL_REPEATER) || defined(SERIAL_REPEATER_USART1)
           case MMDVM_SERIAL:
             writeInt(3U, m_buffer + 3U, m_len - 3U);
             break;
@@ -645,7 +645,7 @@ void CSerialPort::process()
     }
   }
 
-#if defined(SERIAL_REPEATER)
+#if defined(SERIAL_REPEATER) || defined(SERIAL_REPEATER_USART1)
   // Drain any incoming serial data
   while (availableInt(3U))
     readInt(3U);