diff --git a/src/modules/commander/CMakeLists.txt b/src/modules/commander/CMakeLists.txt
index 44d84bca1c..0c9d292462 100644
--- a/src/modules/commander/CMakeLists.txt
+++ b/src/modules/commander/CMakeLists.txt
@@ -37,6 +37,9 @@ px4_add_module(
 	STACK_MAX 2450
 	COMPILE_FLAGS
 		-Wno-sign-compare # TODO: fix all sign-compare
+	INCLUDES
+		# required because of nested includes in mavlink_main.h
+		${PX4_SOURCE_DIR}/mavlink/include/mavlink
 	SRCS
 		commander.cpp
 		state_machine_helper.cpp
diff --git a/src/modules/commander/commander.cpp b/src/modules/commander/commander.cpp
index c0bc54a713..6140833ef1 100644
--- a/src/modules/commander/commander.cpp
+++ b/src/modules/commander/commander.cpp
@@ -84,6 +84,8 @@
 #include <cfloat>
 #include <cstring>
 
+#include <mavlink/mavlink_main.h>
+
 #include <uORB/topics/actuator_armed.h>
 #include <uORB/topics/actuator_controls.h>
 #include <uORB/topics/battery_status.h>
@@ -142,6 +144,9 @@ typedef enum VEHICLE_MODE_FLAG
 
 #define INAIR_RESTART_HOLDOFF_INTERVAL	500000
 
+#define MAVLINK_ENABLE_TRANSMITTING	1	/**< parameter value to enable transmitting for a mavlink instance */
+#define MAVLINK_DISABLE_TRANSMITTING	0	/**< parameter value to disable transmitting for a mavlink instance */
+
 /* Controls the probation period which is the amount of time required for position and velocity checks to pass before the validity can be changed from false to true*/
 #define POSVEL_PROBATION_TAKEOFF 30		/**< probation duration set at takeoff (sec) */
 
@@ -2564,15 +2569,17 @@ Commander::run()
 
 					telemetry_lost[i] = false;
 					have_link = true;
-					if (!telemetry_high_latency[i])
+					if (!telemetry_high_latency[i]) {
 						have_low_latency_link = true;
+					}
 
 				} else if (!telemetry_lost[i]) {
 					/* telemetry was healthy also in last iteration
 					 * we don't have to check a timeout */
 					have_link = true;
-					if (!telemetry_high_latency[i])
+					if (!telemetry_high_latency[i]) {
 						have_low_latency_link = true;
+					}
 				}
 
 			} else {
@@ -2603,8 +2610,8 @@ Commander::run()
 
 				vehicle_command_s vehicle_cmd;
 				vehicle_cmd.command = vehicle_command_s::VEHICLE_CMD_MAVLINK_ENABLE_SENDING;
-				vehicle_cmd.param1 = 6;
-				vehicle_cmd.param2 = 0;
+				vehicle_cmd.param1 = Mavlink::MAVLINK_MODE::MAVLINK_MODE_IRIDIUM;
+				vehicle_cmd.param2 = MAVLINK_DISABLE_TRANSMITTING;
 				if (vehicle_cmd_pub != nullptr) {
 					orb_publish(ORB_ID(vehicle_command), vehicle_cmd_pub, &vehicle_cmd);
 
@@ -2628,8 +2635,8 @@ Commander::run()
 				mavlink_log_critical(&mavlink_log_pub, "ALL LOW LATENCY DATA LINKS LOST, ACTIVATING HIGH LATENCY LINK");
 				vehicle_command_s vehicle_cmd;
 				vehicle_cmd.command = vehicle_command_s::VEHICLE_CMD_MAVLINK_ENABLE_SENDING;
-				vehicle_cmd.param1 = 6;
-				vehicle_cmd.param2 = 1;
+				vehicle_cmd.param1 = Mavlink::MAVLINK_MODE::MAVLINK_MODE_IRIDIUM;
+				vehicle_cmd.param2 = MAVLINK_ENABLE_TRANSMITTING;
 				if (vehicle_cmd_pub != nullptr) {
 					orb_publish(ORB_ID(vehicle_command), vehicle_cmd_pub, &vehicle_cmd);
 
diff --git a/src/modules/mavlink/mavlink_main.cpp b/src/modules/mavlink/mavlink_main.cpp
index e08d23aee3..4c24c2eb7c 100644
--- a/src/modules/mavlink/mavlink_main.cpp
+++ b/src/modules/mavlink/mavlink_main.cpp
@@ -2201,7 +2201,7 @@ Mavlink::task_main(int argc, char *argv[])
 
 		if (cmd_sub->update(&cmd_time, &vehicle_cmd)) {
 			if (vehicle_cmd.command == vehicle_command_s::VEHICLE_CMD_MAVLINK_ENABLE_SENDING) {
-				if (_mode == (int)round(vehicle_cmd.param1)) {
+				if (_mode == (int)roundf(vehicle_cmd.param1)) {
 					if (_transmitting_enabled != (int)vehicle_cmd.param2) {
 						if ((int)vehicle_cmd.param2) {
 							PX4_INFO("Enable transmitting with mavlink instance of type %s on device %s", mavlink_mode_str(_mode), _device_name);