diff --git a/src/modules/mavlink/mavlink_main.cpp b/src/modules/mavlink/mavlink_main.cpp
index 2ae7473860..a45173a4e0 100644
--- a/src/modules/mavlink/mavlink_main.cpp
+++ b/src/modules/mavlink/mavlink_main.cpp
@@ -581,34 +581,6 @@ Mavlink::get_uart_fd(unsigned index)
 	return -1;
 }
 
-int
-Mavlink::get_uart_fd()
-{
-	return _uart_fd;
-}
-
-int
-Mavlink::get_instance_id()
-{
-	return _instance_id;
-}
-
-mavlink_channel_t
-Mavlink::get_channel()
-{
-	return _channel;
-}
-
-int Mavlink::get_system_id()
-{
-	return mavlink_system.sysid;
-}
-
-int Mavlink::get_component_id()
-{
-	return mavlink_system.compid;
-}
-
 int Mavlink::mavlink_open_uart(int baud, const char *uart_name, bool force_flow_control)
 {
 #ifndef B460800
@@ -892,14 +864,6 @@ Mavlink::get_free_tx_buf()
 	return buf_free;
 }
 
-void
-Mavlink::begin_send()
-{
-	// must protect the network buffer so other calls from receive_thread do not
-	// mangle the message.
-	pthread_mutex_lock(&_send_mutex);
-}
-
 int
 Mavlink::send_packet()
 {
@@ -1521,13 +1485,6 @@ Mavlink::message_buffer_count()
 	return n;
 }
 
-int
-Mavlink::message_buffer_is_empty()
-{
-	return _message_buffer.read_ptr == _message_buffer.write_ptr;
-}
-
-
 bool
 Mavlink::message_buffer_write(const void *ptr, int size)
 {
@@ -1589,12 +1546,6 @@ Mavlink::message_buffer_get_ptr(void **ptr, bool *is_part)
 	return n;
 }
 
-void
-Mavlink::message_buffer_mark_read(int n)
-{
-	_message_buffer.read_ptr = (_message_buffer.read_ptr + n) % _message_buffer.size;
-}
-
 void
 Mavlink::pass_message(const mavlink_message_t *msg)
 {
diff --git a/src/modules/mavlink/mavlink_main.h b/src/modules/mavlink/mavlink_main.h
index 512fbba42a..3b0ee86f2c 100644
--- a/src/modules/mavlink/mavlink_main.h
+++ b/src/modules/mavlink/mavlink_main.h
@@ -154,21 +154,21 @@ public:
 
 	static int		get_uart_fd(unsigned index);
 
-	int			get_uart_fd();
+	int			get_uart_fd() const { return _uart_fd; }
 
 	/**
 	 * Get the MAVLink system id.
 	 *
 	 * @return		The system ID of this vehicle
 	 */
-	int			get_system_id();
+	int			get_system_id() const { return mavlink_system.sysid; }
 
 	/**
 	 * Get the MAVLink component id.
 	 *
 	 * @return		The component ID of this vehicle
 	 */
-	int			get_component_id();
+	int			get_component_id() const { return mavlink_system.compid; }
 
 	const char *_device_name;
 
@@ -297,7 +297,7 @@ public:
 	/**
 	 * This is the beginning of a MAVLINK_START_UART_SEND/MAVLINK_END_UART_SEND transaction
 	 */
-	void 			begin_send();
+	void 			begin_send() { pthread_mutex_lock(&_send_mutex); }
 
 	/**
 	 * Send bytes out on the link.
@@ -329,7 +329,7 @@ public:
 	 */
 	MavlinkOrbSubscription *add_orb_subscription(const orb_id_t topic, int instance = 0, bool disable_sharing = false);
 
-	int			get_instance_id();
+	int			get_instance_id() const { return _instance_id; }
 
 	/**
 	 * Enable / disable hardware flow control.
@@ -338,7 +338,7 @@ public:
 	 */
 	int			enable_flow_control(enum FLOW_CONTROL_MODE enabled);
 
-	mavlink_channel_t	get_channel();
+	mavlink_channel_t	get_channel() const { return _channel; }
 
 	void			configure_stream_threadsafe(const char *stream_name, float rate = -1.0f);
 
@@ -678,11 +678,11 @@ private:
 
 	int message_buffer_count();
 
-	int message_buffer_is_empty();
+	int message_buffer_is_empty() const { return (_message_buffer.read_ptr == _message_buffer.write_ptr); }
 
 	int message_buffer_get_ptr(void **ptr, bool *is_part);
 
-	void message_buffer_mark_read(int n);
+	void message_buffer_mark_read(int n) { _message_buffer.read_ptr = (_message_buffer.read_ptr + n) % _message_buffer.size; }
 
 	void pass_message(const mavlink_message_t *msg);