diff --git a/klippy/extras/serial_bridge.py b/klippy/extras/serial_bridge.py
index f22a68f01784..a77ac6530df4 100644
--- a/klippy/extras/serial_bridge.py
+++ b/klippy/extras/serial_bridge.py
@@ -83,7 +83,7 @@ def perform_replacement(self, input_string):
 
         for match in hex_matches:
             hex_value = match.group(1)
-            byte_value = bytes.fromhex(hex_value)
+            byte_value = bytearray.fromhex(hex_value)
             replaced_bytes.extend(byte_value)
             last_index = match.end()
 
@@ -126,7 +126,7 @@ def chunkstring(self, msg, length):
         return (msg[0+i:length+i] for i in range(0, len(msg), length))
 
     def send_text(self, msg):
-        self.send_serial(bytes(msg, encoding='utf-8'))
+        self.send_serial(msg.encode('utf-8'))
 
     def send_serial(self, msg):
         if not self._ready:
@@ -160,6 +160,8 @@ def build_config(self):
     def _handle_serial_bridge_response(self, params):
         data = params["text"]
 
+        data = bytearray(data)
+
         for callback in self.callbacks:
             callback(data)
 
diff --git a/src/stm32/serial_bridge.c b/src/stm32/serial_bridge.c
index 87d839771949..1c442095fc8c 100644
--- a/src/stm32/serial_bridge.c
+++ b/src/stm32/serial_bridge.c
@@ -147,26 +147,33 @@ void serial_bridge_handle_uart_irq(serial_bridge_config_t* config){
     }
 }
 
+#if CONFIG_ENABLE_SERIAL_BRIDGE_USART1
 void
 USART1_serial_bridge_IRQHandler(void)
 {
    serial_bridge_handle_uart_irq(
         serial_bridge_get_active_config_for_usart(USART1));
 }
+#endif
 
+#if CONFIG_ENABLE_SERIAL_BRIDGE_USART2
 void
 USART2_serial_bridge_IRQHandler(void)
 {
     serial_bridge_handle_uart_irq(
         serial_bridge_get_active_config_for_usart(USART2));
 }
+#endif
 
+
+#if CONFIG_ENABLE_SERIAL_BRIDGE_USART6
 void
 USART6_serial_bridge_IRQHandler(void)
 {
     serial_bridge_handle_uart_irq(
         serial_bridge_get_active_config_for_usart(USART6));
 }
+#endif
 
 void
 serial_bridge_enable_tx_irq(int8_t usart_index)