diff --git a/libraries/AP_SerialManager/AP_SerialManager.cpp b/libraries/AP_SerialManager/AP_SerialManager.cpp
index 06afa465f4..f0f910dccd 100644
--- a/libraries/AP_SerialManager/AP_SerialManager.cpp
+++ b/libraries/AP_SerialManager/AP_SerialManager.cpp
@@ -676,6 +676,15 @@ uint32_t AP_SerialManager::find_baudrate(enum SerialProtocol protocol, uint8_t i
     return _state->baudrate();
 }
 
+void AP_SerialManager::set_and_default_baud(enum SerialProtocol protocol, uint8_t instance, uint32_t _baud)
+{
+    const struct UARTState *_state = find_protocol_instance(protocol, instance);
+    if (_state == nullptr) {
+        return;
+    }
+    state->baud.set_and_default(_baud);
+}
+
 // find_portnum - find port number (SERIALn index) for a protocol and instance, -1 for not found
 int8_t AP_SerialManager::find_portnum(enum SerialProtocol protocol, uint8_t instance) const
 {
diff --git a/libraries/AP_SerialManager/AP_SerialManager.h b/libraries/AP_SerialManager/AP_SerialManager.h
index be4a2be0c3..e093e75825 100644
--- a/libraries/AP_SerialManager/AP_SerialManager.h
+++ b/libraries/AP_SerialManager/AP_SerialManager.h
@@ -130,6 +130,8 @@ public:
     // accessors for AP_Periph to set baudrate and type
     void set_protocol_and_baud(uint8_t sernum, enum SerialProtocol protocol, uint32_t baudrate);
 
+    void set_and_default_baud(enum SerialProtocol protocol, uint8_t instance, uint32_t _baud);
+
     static uint32_t map_baudrate(int32_t rate);
 
     // parameter var table