diff --git a/src/drivers/airspeed/airspeed.cpp b/src/drivers/airspeed/airspeed.cpp
index b4570e4bbd..316e88bc59 100644
--- a/src/drivers/airspeed/airspeed.cpp
+++ b/src/drivers/airspeed/airspeed.cpp
@@ -86,8 +86,8 @@ Airspeed::Airspeed(int bus, int address, unsigned conversion_interval, const cha
 	_measure_ticks(0),
 	_collect_phase(false),
 	_diff_pres_offset(0.0f),
-	_airspeed_pub(-1),
-	_subsys_pub(-1),
+	_airspeed_pub(0),
+	_subsys_pub(0),
 	_class_instance(-1),
 	_conversion_interval(conversion_interval),
 	_sample_perf(perf_alloc(PC_ELAPSED, "airspeed_read")),
@@ -146,7 +146,7 @@ Airspeed::init()
 		/* measurement will have generated a report, publish */
 		_airspeed_pub = orb_advertise(ORB_ID(differential_pressure), &arp);
 
-		if (_airspeed_pub < 0)
+		if (_airspeed_pub == 0)
 			warnx("uORB started?");
 	}
 
@@ -367,7 +367,7 @@ Airspeed::update_status()
 			SUBSYSTEM_TYPE_DIFFPRESSURE
 		};
 
-		if (_subsys_pub > 0) {
+		if (_subsys_pub == 0) {
 			orb_publish(ORB_ID(subsystem_info), _subsys_pub, &info);
 		} else {
 			_subsys_pub = orb_advertise(ORB_ID(subsystem_info), &info);
diff --git a/src/drivers/batt_smbus/batt_smbus.cpp b/src/drivers/batt_smbus/batt_smbus.cpp
index 66f959a904..ac9912a0c2 100644
--- a/src/drivers/batt_smbus/batt_smbus.cpp
+++ b/src/drivers/batt_smbus/batt_smbus.cpp
@@ -203,7 +203,7 @@ BATT_SMBUS::BATT_SMBUS(int bus, uint16_t batt_smbus_addr) :
 	_enabled(false),
 	_work{},
 	_reports(nullptr),
-	_batt_topic(-1),
+	_batt_topic(0),
 	_batt_orb_id(nullptr),
 	_start_time(0),
 	_batt_capacity(0)
@@ -427,13 +427,13 @@ BATT_SMBUS::cycle()
 		}
 
 		// publish to orb
-		if (_batt_topic != -1) {
+		if (_batt_topic != 0) {
 			orb_publish(_batt_orb_id, _batt_topic, &new_report);
 
 		} else {
 			_batt_topic = orb_advertise(_batt_orb_id, &new_report);
 
-			if (_batt_topic < 0) {
+			if (_batt_topic == 0) {
 				errx(1, "ADVERT FAIL");
 			}
 		}
diff --git a/src/drivers/bma180/bma180.cpp b/src/drivers/bma180/bma180.cpp
index f4e4622adc..99cadc818d 100644
--- a/src/drivers/bma180/bma180.cpp
+++ b/src/drivers/bma180/bma180.cpp
@@ -238,7 +238,7 @@ BMA180::BMA180(int bus, spi_dev_e device) :
 	_reports(nullptr),
 	_accel_range_scale(0.0f),
 	_accel_range_m_s2(0.0f),
-	_accel_topic(-1),
+	_accel_topic(0),
 	_class_instance(-1),
 	_current_lowpass(0),
 	_current_range(0),
@@ -733,7 +733,7 @@ BMA180::measure()
 	poll_notify(POLLIN);
 
 	/* publish for subscribers */
-	if (_accel_topic > 0 && !(_pub_blocked))
+	if (_accel_topic != 0 && !(_pub_blocked))
 		orb_publish(ORB_ID(sensor_accel), _accel_topic, &report);
 
 	/* stop the perf counter */
diff --git a/src/drivers/gimbal/gimbal.cpp b/src/drivers/gimbal/gimbal.cpp
index db016b363a..eea26417bc 100644
--- a/src/drivers/gimbal/gimbal.cpp
+++ b/src/drivers/gimbal/gimbal.cpp
@@ -180,7 +180,7 @@ Gimbal::Gimbal() :
 	_attitude_compensation_pitch(true),
 	_attitude_compensation_yaw(true),
 	_initialized(false),
-	_actuator_controls_2_topic(-1),
+	_actuator_controls_2_topic(0),
 	_sample_perf(perf_alloc(PC_ELAPSED, "gimbal_read")),
 	_comms_errors(perf_alloc(PC_COUNT, "gimbal_comms_errors")),
 	_buffer_overflows(perf_alloc(PC_COUNT, "gimbal_buffer_overflows"))
@@ -197,7 +197,6 @@ Gimbal::~Gimbal()
 	/* make sure we are truly inactive */
 	stop();
 
-	::close(_actuator_controls_2_topic);
 	::close(_vehicle_command_sub);
 }
 
@@ -281,7 +280,7 @@ Gimbal::cycle()
 		zero_report.timestamp = hrt_absolute_time();
 		_actuator_controls_2_topic = orb_advertise(ORB_ID(actuator_controls_2), &zero_report);
 
-		if (_actuator_controls_2_topic < 0) {
+		if (_actuator_controls_2_topic == 0) {
 			warnx("advert err");
 		}
 
diff --git a/src/drivers/gps/gps.cpp b/src/drivers/gps/gps.cpp
index 965c0e3e5d..3934a24808 100644
--- a/src/drivers/gps/gps.cpp
+++ b/src/drivers/gps/gps.cpp
@@ -175,9 +175,9 @@ GPS::GPS(const char *uart_path, bool fake_gps, bool enable_sat_info) :
 	_mode(GPS_DRIVER_MODE_UBX),
 	_Helper(nullptr),
 	_Sat_Info(nullptr),
-	_report_gps_pos_pub(-1),
+	_report_gps_pos_pub(0),
 	_p_report_sat_info(nullptr),
-	_report_sat_info_pub(-1),
+	_report_sat_info_pub(0),
 	_rate(0.0f),
 	_fake_gps(fake_gps)
 {
diff --git a/src/drivers/hil/hil.cpp b/src/drivers/hil/hil.cpp
index 0e706efc21..16f861350c 100644
--- a/src/drivers/hil/hil.cpp
+++ b/src/drivers/hil/hil.cpp
@@ -805,7 +805,7 @@ fake(int argc, char *argv[])
 
 	orb_advert_t handle = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, &ac);
 
-	if (handle < 0) {
+	if (handle == 0) {
 		puts("advertise failed");
 		return 1;
 	}
diff --git a/src/drivers/hmc5883/hmc5883.cpp b/src/drivers/hmc5883/hmc5883.cpp
index 2d3be15833..d9192bfdbb 100644
--- a/src/drivers/hmc5883/hmc5883.cpp
+++ b/src/drivers/hmc5883/hmc5883.cpp
@@ -360,7 +360,7 @@ HMC5883::HMC5883(device::Device *interface, const char *path, enum Rotation rota
 	_collect_phase(false),
 	_class_instance(-1),
 	_orb_class_instance(-1),
-	_mag_topic(-1),
+	_mag_topic(0),
 	_sample_perf(perf_alloc(PC_ELAPSED, "hmc5883_read")),
 	_comms_errors(perf_alloc(PC_COUNT, "hmc5883_comms_errors")),
 	_buffer_overflows(perf_alloc(PC_COUNT, "hmc5883_buffer_overflows")),
@@ -986,14 +986,14 @@ HMC5883::collect()
 
 	if (!(_pub_blocked)) {
 
-		if (_mag_topic != -1) {
+		if (_mag_topic != 0) {
 			/* publish it */
 			orb_publish(ORB_ID(sensor_mag), _mag_topic, &new_report);
 		} else {
 			_mag_topic = orb_advertise_multi(ORB_ID(sensor_mag), &new_report,
 				&_orb_class_instance, (sensor_is_onboard) ? ORB_PRIO_HIGH : ORB_PRIO_MAX);
 
-			if (_mag_topic < 0)
+			if (_mag_topic == 0)
 				debug("ADVERT FAIL");
 		}
 	}
diff --git a/src/drivers/hott/messages.cpp b/src/drivers/hott/messages.cpp
index f1b12b0678..16256b05d2 100644
--- a/src/drivers/hott/messages.cpp
+++ b/src/drivers/hott/messages.cpp
@@ -63,7 +63,7 @@ static int _sensor_sub = -1;
 static int _airspeed_sub = -1;
 static int _esc_sub = -1;
 
-static orb_advert_t _esc_pub;
+static orb_advert_t _esc_pub = 0;
 
 static bool _home_position_set = false;
 static double _home_lat = 0.0d;
diff --git a/src/drivers/l3gd20/l3gd20.cpp b/src/drivers/l3gd20/l3gd20.cpp
index f276b67f00..810fa9135d 100644
--- a/src/drivers/l3gd20/l3gd20.cpp
+++ b/src/drivers/l3gd20/l3gd20.cpp
@@ -411,7 +411,7 @@ L3GD20::L3GD20(int bus, const char* path, spi_dev_e device, enum Rotation rotati
 	_gyro_scale{},
 	_gyro_range_scale(0.0f),
 	_gyro_range_rad_s(0.0f),
-	_gyro_topic(-1),
+	_gyro_topic(0),
 	_orb_class_instance(-1),
 	_class_instance(-1),
 	_current_rate(0),
@@ -490,7 +490,7 @@ L3GD20::init()
 	_gyro_topic = orb_advertise_multi(ORB_ID(sensor_gyro), &grp,
 		&_orb_class_instance, (is_external()) ? ORB_PRIO_VERY_HIGH : ORB_PRIO_DEFAULT);
 
-	if (_gyro_topic < 0) {
+	if (_gyro_topic == 0) {
 		debug("failed to create sensor_gyro publication");
 	}
 
diff --git a/src/drivers/lsm303d/lsm303d.cpp b/src/drivers/lsm303d/lsm303d.cpp
index 8a77eeb917..df80f26d7a 100644
--- a/src/drivers/lsm303d/lsm303d.cpp
+++ b/src/drivers/lsm303d/lsm303d.cpp
@@ -563,7 +563,7 @@ LSM303D::LSM303D(int bus, const char* path, spi_dev_e device, enum Rotation rota
 	_mag_range_ga(0.0f),
 	_mag_range_scale(0.0f),
 	_mag_samplerate(0),
-	_accel_topic(-1),
+	_accel_topic(0),
 	_accel_orb_class_instance(-1),
 	_accel_class_instance(-1),
 	_accel_read(0),
@@ -676,7 +676,7 @@ LSM303D::init()
 	_mag->_mag_topic = orb_advertise_multi(ORB_ID(sensor_mag), &mrp,
 		&_mag->_mag_orb_class_instance, ORB_PRIO_LOW);
 
-	if (_mag->_mag_topic < 0) {
+	if (_mag->_mag_topic == 0) {
 		warnx("ADVERT ERR");
 	}
 
@@ -691,7 +691,7 @@ LSM303D::init()
 	_accel_topic = orb_advertise_multi(ORB_ID(sensor_accel), &arp,
 		&_accel_orb_class_instance, (is_external()) ? ORB_PRIO_VERY_HIGH : ORB_PRIO_DEFAULT);
 
-	if (_accel_topic < 0) {
+	if (_accel_topic == 0) {
 		warnx("ADVERT ERR");
 	}
 
@@ -1770,7 +1770,7 @@ LSM303D::test_error()
 LSM303D_mag::LSM303D_mag(LSM303D *parent) :
 	CDev("LSM303D_mag", LSM303D_DEVICE_PATH_MAG),
 	_parent(parent),
-	_mag_topic(-1),
+	_mag_topic(0),
 	_mag_orb_class_instance(-1),
 	_mag_class_instance(-1)
 {
diff --git a/src/drivers/mb12xx/mb12xx.cpp b/src/drivers/mb12xx/mb12xx.cpp
index afeb8e5545..a191ec0be2 100644
--- a/src/drivers/mb12xx/mb12xx.cpp
+++ b/src/drivers/mb12xx/mb12xx.cpp
@@ -211,7 +211,7 @@ MB12XX::MB12XX(int bus, int address) :
 	_collect_phase(false),
 	_class_instance(-1),
 	_orb_class_instance(-1),
-	_distance_sensor_topic(-1),
+	_distance_sensor_topic(nullptr),
 	_sample_perf(perf_alloc(PC_ELAPSED, "mb12xx_read")),
 	_comms_errors(perf_alloc(PC_COUNT, "mb12xx_comms_errors")),
 	_buffer_overflows(perf_alloc(PC_COUNT, "mb12xx_buffer_overflows")),
@@ -276,7 +276,7 @@ MB12XX::init()
 		_distance_sensor_topic = orb_advertise_multi(ORB_ID(distance_sensor), &ds_report,
 							     &_orb_class_instance, ORB_PRIO_LOW);
 
-		if (_distance_sensor_topic < 0) {
+		if (_distance_sensor_topic == nullptr) {
 			log("failed to create distance_sensor object. Did you start uOrb?");
 		}
 	}
@@ -588,7 +588,7 @@ MB12XX::collect()
 	report.id = 0;
 
 	/* publish it, if we are the primary */
-	if (_distance_sensor_topic >= 0) {
+	if (_distance_sensor_topic != nullptr) {
 		orb_publish(ORB_ID(distance_sensor), _distance_sensor_topic, &report);
 	}
 
diff --git a/src/drivers/mkblctrl/mkblctrl.cpp b/src/drivers/mkblctrl/mkblctrl.cpp
index d1484a2f01..c9ca1843e5 100644
--- a/src/drivers/mkblctrl/mkblctrl.cpp
+++ b/src/drivers/mkblctrl/mkblctrl.cpp
@@ -641,7 +641,6 @@ MK::task_main()
 
 	}
 
-	::close(_t_esc_status);
 	::close(_t_actuators);
 	::close(_t_actuator_armed);
 
diff --git a/src/drivers/mpu6000/mpu6000.cpp b/src/drivers/mpu6000/mpu6000.cpp
index 7049bd0788..b2bec363e7 100644
--- a/src/drivers/mpu6000/mpu6000.cpp
+++ b/src/drivers/mpu6000/mpu6000.cpp
@@ -507,7 +507,7 @@ MPU6000::MPU6000(int bus, const char *path_accel, const char *path_gyro, spi_dev
 	_accel_scale{},
 	_accel_range_scale(0.0f),
 	_accel_range_m_s2(0.0f),
-	_accel_topic(-1),
+	_accel_topic(0),
 	_accel_orb_class_instance(-1),
 	_accel_class_instance(-1),
 	_gyro_reports(nullptr),
@@ -658,7 +658,7 @@ MPU6000::init()
 	_accel_topic = orb_advertise_multi(ORB_ID(sensor_accel), &arp,
 		&_accel_orb_class_instance, (is_external()) ? ORB_PRIO_MAX : ORB_PRIO_HIGH);
 
-	if (_accel_topic < 0) {
+	if (_accel_topic == 0) {
 		warnx("ADVERT FAIL");
 	}
 
@@ -670,7 +670,7 @@ MPU6000::init()
 	_gyro->_gyro_topic = orb_advertise_multi(ORB_ID(sensor_gyro), &grp,
 		&_gyro->_gyro_orb_class_instance, (is_external()) ? ORB_PRIO_MAX : ORB_PRIO_HIGH);
 
-	if (_gyro->_gyro_topic < 0) {
+	if (_gyro->_gyro_topic == 0) {
 		warnx("ADVERT FAIL");
 	}
 
@@ -1847,7 +1847,7 @@ MPU6000::print_registers()
 MPU6000_gyro::MPU6000_gyro(MPU6000 *parent, const char *path) :
 	CDev("MPU6000_gyro", path),
 	_parent(parent),
-	_gyro_topic(-1),
+	_gyro_topic(0),
 	_gyro_orb_class_instance(-1),
 	_gyro_class_instance(-1)
 {
diff --git a/src/drivers/ms5611/ms5611_nuttx.cpp b/src/drivers/ms5611/ms5611_nuttx.cpp
index cf96a7a95b..050eb5be46 100644
--- a/src/drivers/ms5611/ms5611_nuttx.cpp
+++ b/src/drivers/ms5611/ms5611_nuttx.cpp
@@ -224,7 +224,7 @@ MS5611::MS5611(device::Device *interface, ms5611::prom_u &prom_buf, const char*
 	_OFF(0),
 	_SENS(0),
 	_msl_pressure(101325),
-	_baro_topic(-1),
+	_baro_topic(0),
 	_orb_class_instance(-1),
 	_class_instance(-1),
 	_sample_perf(perf_alloc(PC_ELAPSED, "ms5611_read")),
@@ -322,7 +322,7 @@ MS5611::init()
 				&_orb_class_instance, (is_external()) ? ORB_PRIO_HIGH : ORB_PRIO_DEFAULT);
 
 
-		if (_baro_topic < 0) {
+		if (_baro_topic == 0) {
 			warnx("failed to create sensor_baro publication");
 		}
 
diff --git a/src/drivers/ms5611/ms5611_posix.cpp b/src/drivers/ms5611/ms5611_posix.cpp
index 9e99d926e2..701765c84b 100644
--- a/src/drivers/ms5611/ms5611_posix.cpp
+++ b/src/drivers/ms5611/ms5611_posix.cpp
@@ -223,7 +223,7 @@ MS5611::MS5611(device::Device *interface, ms5611::prom_u &prom_buf, const char*
 	_OFF(0),
 	_SENS(0),
 	_msl_pressure(101325),
-	_baro_topic(-1),
+	_baro_topic(0),
 	_orb_class_instance(-1),
 	_class_instance(-1),
 	_sample_perf(perf_alloc(PC_ELAPSED, "ms5611_read")),
@@ -325,7 +325,7 @@ MS5611::init()
 		_baro_topic = orb_advertise_multi(ORB_ID(sensor_baro), &brp,
 				&_orb_class_instance, (is_external()) ? ORB_PRIO_HIGH : ORB_PRIO_DEFAULT);
 
-		if (_baro_topic == (orb_advert_t)(-1)) {
+		if (_baro_topic == 0) {
 			warnx("failed to create sensor_baro publication");
 		}
 		//warnx("sensor_baro publication %ld", _baro_topic);
diff --git a/src/drivers/px4flow/px4flow.cpp b/src/drivers/px4flow/px4flow.cpp
index db721afe32..d4cfec9a39 100644
--- a/src/drivers/px4flow/px4flow.cpp
+++ b/src/drivers/px4flow/px4flow.cpp
@@ -193,8 +193,8 @@ PX4FLOW::PX4FLOW(int bus, int address, enum Rotation rotation) :
 	_collect_phase(false),
 	_class_instance(-1),
 	_orb_class_instance(-1),
-	_px4flow_topic(-1),
-	_distance_sensor_topic(-1),
+	_px4flow_topic(nullptr),
+	_distance_sensor_topic(nullptr),
 	_sample_perf(perf_alloc(PC_ELAPSED, "px4flow_read")),
 	_comms_errors(perf_alloc(PC_COUNT, "px4flow_comms_errors")),
 	_buffer_overflows(perf_alloc(PC_COUNT, "px4flow_buffer_overflows")),
@@ -517,7 +517,7 @@ PX4FLOW::collect()
 	float zeroval = 0.0f;
 	rotate_3f(_sensor_rotation, report.pixel_flow_x_integral, report.pixel_flow_y_integral, zeroval);
 
-	if (_px4flow_topic < 0) {
+	if (_px4flow_topic == 0) {
 		_px4flow_topic = orb_advertise(ORB_ID(optical_flow), &report);
 
 	} else {
diff --git a/src/drivers/sf0x/sf0x.cpp b/src/drivers/sf0x/sf0x.cpp
index 431184d046..e117927022 100644
--- a/src/drivers/sf0x/sf0x.cpp
+++ b/src/drivers/sf0x/sf0x.cpp
@@ -200,7 +200,7 @@ SF0X::SF0X(const char *port) :
 	_last_read(0),
 	_class_instance(-1),
 	_orb_class_instance(-1),
-	_distance_sensor_topic(-1),
+	_distance_sensor_topic(nullptr),
 	_consecutive_fail_count(0),
 	_sample_perf(perf_alloc(PC_ELAPSED, "sf0x_read")),
 	_comms_errors(perf_alloc(PC_COUNT, "sf0x_comms_errors")),
@@ -293,6 +293,7 @@ SF0X::init()
 
 		_class_instance = register_class_devname(RANGE_FINDER_BASE_DEVICE_PATH);
 
+<<<<<<< HEAD
 		if (_class_instance == CLASS_DEVICE_PRIMARY) {
 			/* get a publish handle on the range finder topic */
 			struct distance_sensor_s ds_report = {};
@@ -303,6 +304,10 @@ SF0X::init()
 			if (_distance_sensor_topic < 0) {
 				log("failed to create distance_sensor object. Did you start uOrb?");
 			}
+=======
+		if (_range_finder_topic == 0) {
+			warnx("advert err");
+>>>>>>> extensive orb_advert_t fixes
 		}
 
 	} while(0);
diff --git a/src/drivers/trone/trone.cpp b/src/drivers/trone/trone.cpp
index 23e52547a1..992669fffb 100644
--- a/src/drivers/trone/trone.cpp
+++ b/src/drivers/trone/trone.cpp
@@ -238,7 +238,7 @@ TRONE::TRONE(int bus, int address) :
 	_collect_phase(false),
 	_class_instance(-1),
 	_orb_class_instance(-1),
-	_distance_sensor_topic(-1),
+	_distance_sensor_topic(0),
 	_sample_perf(perf_alloc(PC_ELAPSED, "trone_read")),
 	_comms_errors(perf_alloc(PC_COUNT, "trone_comms_errors")),
 	_buffer_overflows(perf_alloc(PC_COUNT, "trone_buffer_overflows"))
@@ -301,7 +301,7 @@ TRONE::init()
 		_distance_sensor_topic = orb_advertise_multi(ORB_ID(distance_sensor), &ds_report,
 							     &_orb_class_instance, ORB_PRIO_LOW);
 
-		if (_distance_sensor_topic < 0) {
+		if (_distance_sensor_topic == 0) {
 			log("failed to create distance_sensor object. Did you start uOrb?");
 		}
 	}
@@ -587,7 +587,7 @@ TRONE::collect()
 	report.id = 0;
 
 	/* publish it, if we are the primary */
-	if (_distance_sensor_topic >= 0) {
+	if (_distance_sensor_topic != nullptr) {
 		orb_publish(ORB_ID(distance_sensor), _distance_sensor_topic, &report);
 	}
 
@@ -621,9 +621,9 @@ TRONE::start()
 		true,
 		SUBSYSTEM_TYPE_RANGEFINDER
 	};
-	static orb_advert_t pub = -1;
+	static orb_advert_t pub = nullptr;
 
-	if (pub > 0) {
+	if (pub != nullptr) {
 		orb_publish(ORB_ID(subsystem_info), pub, &info);
 
 	} else {
diff --git a/src/examples/hwtest/hwtest.c b/src/examples/hwtest/hwtest.c
index 298f13e842..a403f2fa24 100644
--- a/src/examples/hwtest/hwtest.c
+++ b/src/examples/hwtest/hwtest.c
@@ -63,7 +63,7 @@ int ex_hwtest_main(int argc, char *argv[])
 
 	struct actuator_controls_s actuators;
 	memset(&actuators, 0, sizeof(actuators));
-	orb_advert_t actuator_pub_fd = orb_advertise(ORB_ID(actuator_controls_0), &actuators);
+	orb_advert_t actuator_pub_ptr = orb_advertise(ORB_ID(actuator_controls_0), &actuators);
 
 	struct actuator_armed_s arm;
 	memset(&arm, 0 , sizeof(arm));
@@ -71,8 +71,8 @@ int ex_hwtest_main(int argc, char *argv[])
 	arm.timestamp = hrt_absolute_time();
 	arm.ready_to_arm = true;
 	arm.armed = true;
-	orb_advert_t arm_pub_fd = orb_advertise(ORB_ID(actuator_armed), &arm);
-	orb_publish(ORB_ID(actuator_armed), arm_pub_fd, &arm);
+	orb_advert_t arm_pub_ptr = orb_advertise(ORB_ID(actuator_armed), &arm);
+	orb_publish(ORB_ID(actuator_armed), arm_pub_ptr, &arm);
 
 	/* read back values to validate */
 	int arm_sub_fd = orb_subscribe(ORB_ID(actuator_armed));
@@ -118,7 +118,7 @@ int ex_hwtest_main(int argc, char *argv[])
 			}
 
 			actuators.timestamp = hrt_absolute_time();
-			orb_publish(ORB_ID(actuator_controls_0), actuator_pub_fd, &actuators);
+			orb_publish(ORB_ID(actuator_controls_0), actuator_pub_ptr, &actuators);
 			usleep(10000);
 		}
 
diff --git a/src/modules/attitude_estimator_q/attitude_estimator_q_main.cpp b/src/modules/attitude_estimator_q/attitude_estimator_q_main.cpp
index f9099cd167..9d46cf5744 100644
--- a/src/modules/attitude_estimator_q/attitude_estimator_q_main.cpp
+++ b/src/modules/attitude_estimator_q/attitude_estimator_q_main.cpp
@@ -114,7 +114,7 @@ private:
 	int		_sensors_sub = -1;
 	int		_params_sub = -1;
 	int		_global_pos_sub = -1;
-	orb_advert_t		_att_pub = -1;
+	orb_advert_t		_att_pub = 0;
 
 	struct {
 		param_t	w_acc;
@@ -327,7 +327,7 @@ void AttitudeEstimatorQ::task_main() {
 		memcpy(&att.R[0], R.data, sizeof(att.R));
 		att.R_valid = true;
 
-		if (_att_pub < 0) {
+		if (_att_pub == 0) {
 			_att_pub = orb_advertise(ORB_ID(vehicle_attitude), &att);
 		} else {
 			orb_publish(ORB_ID(vehicle_attitude), _att_pub, &att);
diff --git a/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp b/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp
index 68a61488f9..c8c740e273 100755
--- a/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp
+++ b/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp
@@ -432,8 +432,6 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 	int sub_control_mode = orb_subscribe(ORB_ID(vehicle_control_mode));
 
 	/* advertise attitude */
-	//orb_advert_t pub_att = orb_advertise(ORB_ID(vehicle_attitude), &att);
-	//orb_advert_t att_pub = -1;
 	orb_advert_t att_pub = orb_advertise(ORB_ID(vehicle_attitude), &att);
 
 	int loopcounter = 0;
diff --git a/src/modules/bottle_drop/bottle_drop.cpp b/src/modules/bottle_drop/bottle_drop.cpp
index 987b930d28..3a94de899d 100644
--- a/src/modules/bottle_drop/bottle_drop.cpp
+++ b/src/modules/bottle_drop/bottle_drop.cpp
@@ -180,7 +180,7 @@ BottleDrop::BottleDrop() :
 	_command {},
 	_global_pos {},
 	ref {},
-	_actuator_pub(-1),
+	_actuator_pub(0),
 	_actuators {},
 	_drop_approval(false),
 	_doors_opened(0),
@@ -190,7 +190,7 @@ BottleDrop::BottleDrop() :
 	_drop_position {},
 	_drop_state(DROP_STATE_INIT),
 	_onboard_mission {},
-	_onboard_mission_pub(-1)
+	_onboard_mission_pub(0)
 {
 }
 
diff --git a/src/modules/commander/commander.cpp b/src/modules/commander/commander.cpp
index f81cbfb2b6..d924256401 100644
--- a/src/modules/commander/commander.cpp
+++ b/src/modules/commander/commander.cpp
@@ -934,7 +934,7 @@ int commander_thread_main(int argc, char *argv[])
 	/* publish initial state */
 	status_pub = orb_advertise(ORB_ID(vehicle_status), &status);
 
-	if (status_pub < 0) {
+	if (status_pub == 0) {
 		warnx("ERROR: orb_advertise for topic vehicle_status failed (uorb app running?).\n");
 		warnx("exiting.");
 		px4_task_exit(ERROR);
@@ -952,12 +952,12 @@ int commander_thread_main(int argc, char *argv[])
 	armed_pub = orb_advertise(ORB_ID(actuator_armed), &armed);
 
 	/* home position */
-	orb_advert_t home_pub = -1;
+	orb_advert_t home_pub = 0;
 	struct home_position_s home;
 	memset(&home, 0, sizeof(home));
 
 	/* init mission state, do it here to allow navigator to use stored mission even if mavlink failed to start */
-	orb_advert_t mission_pub = -1;
+	orb_advert_t mission_pub = 0;
 	mission_s mission;
 
 	if (dm_read(DM_KEY_MISSION_STATE, 0, &mission, sizeof(mission_s)) == sizeof(mission_s)) {
@@ -2124,7 +2124,6 @@ int commander_thread_main(int argc, char *argv[])
 	close(diff_pres_sub);
 	close(param_changed_sub);
 	close(battery_sub);
-	close(mission_pub);
 
 	thread_running = false;
 
diff --git a/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp b/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp
index c04d79f4e7..a12f78b32c 100644
--- a/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp
+++ b/src/modules/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp
@@ -129,11 +129,11 @@ AttitudePositionEstimatorEKF::AttitudePositionEstimatorEKF() :
 	_armedSub(-1),
 
 /* publications */
-	_att_pub(-1),
-	_global_pos_pub(-1),
-	_local_pos_pub(-1),
-	_estimator_status_pub(-1),
-	_wind_pub(-1),
+	_att_pub(0),
+	_global_pos_pub(0),
+	_local_pos_pub(0),
+	_estimator_status_pub(0),
+	_wind_pub(0),
 
 	_att({}),
     _gyro({}),
diff --git a/src/modules/fw_att_control/fw_att_control_main.cpp b/src/modules/fw_att_control/fw_att_control_main.cpp
index cb17728948..387956f693 100644
--- a/src/modules/fw_att_control/fw_att_control_main.cpp
+++ b/src/modules/fw_att_control/fw_att_control_main.cpp
@@ -337,10 +337,10 @@ FixedwingAttitudeControl::FixedwingAttitudeControl() :
 	_vehicle_status_sub(-1),
 
 /* publications */
-	_rate_sp_pub(-1),
-	_attitude_sp_pub(-1),
-	_actuators_0_pub(-1),
-	_actuators_2_pub(-1),
+	_rate_sp_pub(0),
+	_attitude_sp_pub(0),
+	_actuators_0_pub(0),
+	_actuators_2_pub(0),
 
 	_rates_sp_id(0),
 	_actuators_id(0),
diff --git a/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp b/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp
index 3525c5674b..fc21fc9b5d 100644
--- a/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp
+++ b/src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp
@@ -434,9 +434,9 @@ FixedwingPositionControl::FixedwingPositionControl() :
 	_sensor_combined_sub(-1),
 
 /* publications */
-	_attitude_sp_pub(-1),
-	_tecs_status_pub(-1),
-	_nav_capabilities_pub(-1),
+	_attitude_sp_pub(0),
+	_tecs_status_pub(0),
+	_nav_capabilities_pub(0),
 
 /* states */
 	_att(),
diff --git a/src/modules/land_detector/LandDetector.cpp b/src/modules/land_detector/LandDetector.cpp
index 7c830fc072..d7e2f8101f 100644
--- a/src/modules/land_detector/LandDetector.cpp
+++ b/src/modules/land_detector/LandDetector.cpp
@@ -44,7 +44,7 @@
 #include <drivers/drv_hrt.h>
 
 LandDetector::LandDetector() :
-	_landDetectedPub(-1),
+	_landDetectedPub(0),
 	_landDetected({0, false}),
 	      _taskShouldExit(false),
 	      _taskIsRunning(false)
@@ -55,7 +55,6 @@ LandDetector::LandDetector() :
 LandDetector::~LandDetector()
 {
 	_taskShouldExit = true;
-	close(_landDetectedPub);
 }
 
 void LandDetector::shutdown()
diff --git a/src/modules/mavlink/mavlink_mission.cpp b/src/modules/mavlink/mavlink_mission.cpp
index 442d36dfba..5546996edb 100644
--- a/src/modules/mavlink/mavlink_mission.cpp
+++ b/src/modules/mavlink/mavlink_mission.cpp
@@ -81,7 +81,7 @@ MavlinkMissionManager::MavlinkMissionManager(Mavlink *mavlink) : MavlinkStream(m
 	_transfer_partner_compid(0),
 	_offboard_mission_sub(-1),
 	_mission_result_sub(-1),
-	_offboard_mission_pub(-1),
+	_offboard_mission_pub(0),
 	_slow_rate_limiter(_interval / 10.0f),
 	_verbose(false)
 {
@@ -93,7 +93,6 @@ MavlinkMissionManager::MavlinkMissionManager(Mavlink *mavlink) : MavlinkStream(m
 
 MavlinkMissionManager::~MavlinkMissionManager()
 {
-	close(_offboard_mission_pub);
 	close(_mission_result_sub);
 }
 
@@ -150,7 +149,7 @@ MavlinkMissionManager::update_active_mission(int dataman_id, unsigned count, int
 		_current_seq = seq;
 
 		/* mission state saved successfully, publish offboard_mission topic */
-		if (_offboard_mission_pub < 0) {
+		if (_offboard_mission_pub == 0) {
 			_offboard_mission_pub = orb_advertise(ORB_ID(offboard_mission), &mission);
 
 		} else {
diff --git a/src/modules/mavlink/mavlink_parameters.cpp b/src/modules/mavlink/mavlink_parameters.cpp
index 524effb205..5c13629513 100644
--- a/src/modules/mavlink/mavlink_parameters.cpp
+++ b/src/modules/mavlink/mavlink_parameters.cpp
@@ -45,7 +45,7 @@
 
 MavlinkParametersManager::MavlinkParametersManager(Mavlink *mavlink) : MavlinkStream(mavlink),
 	_send_all_index(-1),
-	_rc_param_map_pub(-1),
+	_rc_param_map_pub(0),
 	_rc_param_map()
 {
 }
@@ -162,7 +162,7 @@ MavlinkParametersManager::handle_message(const mavlink_message_t *msg)
 				}
 				_rc_param_map.timestamp = hrt_absolute_time();
 
-				if (_rc_param_map_pub < 0) {
+				if (_rc_param_map_pub == 0) {
 					_rc_param_map_pub = orb_advertise(ORB_ID(rc_parameter_map), &_rc_param_map);
 
 				} else {
diff --git a/src/modules/mavlink/mavlink_receiver.cpp b/src/modules/mavlink/mavlink_receiver.cpp
index 8a9b426484..d9b666a003 100644
--- a/src/modules/mavlink/mavlink_receiver.cpp
+++ b/src/modules/mavlink/mavlink_receiver.cpp
@@ -95,34 +95,34 @@ MavlinkReceiver::MavlinkReceiver(Mavlink *parent) :
 	hil_local_pos{},
 	hil_land_detector{},
 	_control_mode{},
-	_global_pos_pub(-1),
-	_local_pos_pub(-1),
-	_attitude_pub(-1),
-	_gps_pub(-1),
-	_sensors_pub(-1),
-	_gyro_pub(-1),
-	_accel_pub(-1),
-	_mag_pub(-1),
-	_baro_pub(-1),
-	_airspeed_pub(-1),
-	_battery_pub(-1),
-	_cmd_pub(-1),
-	_flow_pub(-1),
-	_distance_sensor_pub(-1),
-	_offboard_control_mode_pub(-1),
-	_actuator_controls_pub(-1),
-	_global_vel_sp_pub(-1),
-	_att_sp_pub(-1),
-	_rates_sp_pub(-1),
-	_force_sp_pub(-1),
-	_pos_sp_triplet_pub(-1),
-	_vicon_position_pub(-1),
-	_vision_position_pub(-1),
-	_telemetry_status_pub(-1),
-	_rc_pub(-1),
-	_manual_pub(-1),
-	_land_detector_pub(-1),
-	_time_offset_pub(-1),
+	_global_pos_pub(0),
+	_local_pos_pub(0),
+	_attitude_pub(0),
+	_gps_pub(0),
+	_sensors_pub(0),
+	_gyro_pub(0),
+	_accel_pub(0),
+	_mag_pub(0),
+	_baro_pub(0),
+	_airspeed_pub(0),
+	_battery_pub(0),
+	_cmd_pub(0),
+	_flow_pub(0),
+	_distance_sensor_pub(0),
+	_offboard_control_mode_pub(0),
+	_actuator_controls_pub(0),
+	_global_vel_sp_pub(0),
+	_att_sp_pub(0),
+	_rates_sp_pub(0),
+	_force_sp_pub(0),
+	_pos_sp_triplet_pub(0),
+	_vicon_position_pub(0),
+	_vision_position_pub(0),
+	_telemetry_status_pub(0),
+	_rc_pub(0),
+	_manual_pub(0),
+	_land_detector_pub(0),
+	_time_offset_pub(0),
 	_control_mode_sub(orb_subscribe(ORB_ID(vehicle_control_mode))),
 	_hil_frames(0),
 	_old_timestamp(0),
@@ -314,7 +314,7 @@ MavlinkReceiver::handle_message_command_long(mavlink_message_t *msg)
 			vcmd.source_component = msg->compid;
 			vcmd.confirmation =  cmd_mavlink.confirmation;
 
-			if (_cmd_pub < 0) {
+			if (_cmd_pub == 0) {
 				_cmd_pub = orb_advertise(ORB_ID(vehicle_command), &vcmd);
 
 			} else {
@@ -370,7 +370,7 @@ MavlinkReceiver::handle_message_command_int(mavlink_message_t *msg)
 			vcmd.source_system = msg->sysid;
 			vcmd.source_component = msg->compid;
 
-			if (_cmd_pub < 0) {
+			if (_cmd_pub == 0) {
 				_cmd_pub = orb_advertise(ORB_ID(vehicle_command), &vcmd);
 
 			} else {
@@ -410,7 +410,7 @@ MavlinkReceiver::handle_message_optical_flow_rad(mavlink_message_t *msg)
 	float zeroval = 0.0f;
 	rotate_3f(flow_rot, f.pixel_flow_x_integral, f.pixel_flow_y_integral, zeroval);
 
-	if (_flow_pub < 0) {
+	if (_flow_pub == 0) {
 		_flow_pub = orb_advertise(ORB_ID(optical_flow), &f);
 
 	} else {
@@ -461,7 +461,7 @@ MavlinkReceiver::handle_message_hil_optical_flow(mavlink_message_t *msg)
 	f.sensor_id = flow.sensor_id;
 	f.gyro_temperature = flow.temperature;
 
-	if (_flow_pub < 0) {
+	if (_flow_pub == 0) {
 		_flow_pub = orb_advertise(ORB_ID(optical_flow), &f);
 
 	} else {
@@ -515,7 +515,7 @@ MavlinkReceiver::handle_message_set_mode(mavlink_message_t *msg)
 	vcmd.source_component = msg->compid;
 	vcmd.confirmation = 1;
 
-	if (_cmd_pub < 0) {
+	if (_cmd_pub == 0) {
 		_cmd_pub = orb_advertise(ORB_ID(vehicle_command), &vcmd);
 
 	} else {
@@ -570,7 +570,7 @@ MavlinkReceiver::handle_message_vicon_position_estimate(mavlink_message_t *msg)
 	vicon_position.pitch = pos.pitch;
 	vicon_position.yaw = pos.yaw;
 
-	if (_vicon_position_pub < 0) {
+	if (_vicon_position_pub == 0) {
 		_vicon_position_pub = orb_advertise(ORB_ID(vehicle_vicon_position), &vicon_position);
 
 	} else {
@@ -605,7 +605,7 @@ MavlinkReceiver::handle_message_set_position_target_local_ned(mavlink_message_t
 
 		offboard_control_mode.timestamp = hrt_absolute_time();
 
-		if (_offboard_control_mode_pub < 0) {
+		if (_offboard_control_mode_pub == 0) {
 			_offboard_control_mode_pub = orb_advertise(ORB_ID(offboard_control_mode), &offboard_control_mode);
 
 		} else {
@@ -630,7 +630,7 @@ MavlinkReceiver::handle_message_set_position_target_local_ned(mavlink_message_t
 					force_sp.y = set_position_target_local_ned.afy;
 					force_sp.z = set_position_target_local_ned.afz;
 					//XXX: yaw
-					if (_force_sp_pub < 0) {
+					if (_force_sp_pub == 0) {
 						_force_sp_pub = orb_advertise(ORB_ID(vehicle_force_setpoint), &force_sp);
 					} else {
 						orb_publish(ORB_ID(vehicle_force_setpoint), _force_sp_pub, &force_sp);
@@ -697,7 +697,7 @@ MavlinkReceiver::handle_message_set_position_target_local_ned(mavlink_message_t
 					//XXX handle global pos setpoints (different MAV frames)
 
 
-					if (_pos_sp_triplet_pub < 0) {
+					if (_pos_sp_triplet_pub == 0) {
 						_pos_sp_triplet_pub = orb_advertise(ORB_ID(position_setpoint_triplet),
 								&pos_sp_triplet);
 					} else {
@@ -740,7 +740,7 @@ MavlinkReceiver::handle_message_set_actuator_control_target(mavlink_message_t *m
 
 		offboard_control_mode.timestamp = hrt_absolute_time();
 
-		if (_offboard_control_mode_pub < 0) {
+		if (_offboard_control_mode_pub == 0) {
 			_offboard_control_mode_pub = orb_advertise(ORB_ID(offboard_control_mode), &offboard_control_mode);
 		} else {
 			orb_publish(ORB_ID(offboard_control_mode), _offboard_control_mode_pub, &offboard_control_mode);
@@ -763,7 +763,7 @@ MavlinkReceiver::handle_message_set_actuator_control_target(mavlink_message_t *m
 				actuator_controls.control[i] = set_actuator_control_target.controls[i];
 			}
 
-			if (_actuator_controls_pub < 0) {
+			if (_actuator_controls_pub == 0) {
 				_actuator_controls_pub = orb_advertise(ORB_ID(actuator_controls_0), &actuator_controls);
 			} else {
 				orb_publish(ORB_ID(actuator_controls_0), _actuator_controls_pub, &actuator_controls);
@@ -804,7 +804,7 @@ MavlinkReceiver::handle_message_vision_position_estimate(mavlink_message_t *msg)
 	vision_position.q[2] = q(2);
 	vision_position.q[3] = q(3);
 
-	if (_vision_position_pub < 0) {
+	if (_vision_position_pub == 0) {
 		_vision_position_pub = orb_advertise(ORB_ID(vision_position_estimate), &vision_position);
 
 	} else {
@@ -857,7 +857,7 @@ MavlinkReceiver::handle_message_set_attitude_target(mavlink_message_t *msg)
 
 		_offboard_control_mode.timestamp = hrt_absolute_time();
 
-		if (_offboard_control_mode_pub < 0) {
+		if (_offboard_control_mode_pub == 0) {
 			_offboard_control_mode_pub = orb_advertise(ORB_ID(offboard_control_mode), &_offboard_control_mode);
 
 		} else {
@@ -892,7 +892,7 @@ MavlinkReceiver::handle_message_set_attitude_target(mavlink_message_t *msg)
 						_att_sp.thrust = set_attitude_target.thrust;
 					}
 
-					if (_att_sp_pub < 0) {
+					if (_att_sp_pub == 0) {
 						_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);
 					} else {
 						orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &_att_sp);
@@ -912,7 +912,7 @@ MavlinkReceiver::handle_message_set_attitude_target(mavlink_message_t *msg)
 						_rates_sp.thrust = set_attitude_target.thrust;
 					}
 
-					if (_att_sp_pub < 0) {
+					if (_att_sp_pub == 0) {
 						_rates_sp_pub = orb_advertise(ORB_ID(vehicle_rates_setpoint), &_rates_sp);
 					} else {
 						orb_publish(ORB_ID(vehicle_rates_setpoint), _rates_sp_pub, &_rates_sp);
@@ -948,7 +948,7 @@ MavlinkReceiver::handle_message_radio_status(mavlink_message_t *msg)
 		tstatus.system_id = msg->sysid;
 		tstatus.component_id = msg->compid;
 
-		if (_telemetry_status_pub < 0) {
+		if (_telemetry_status_pub == 0) {
 			_telemetry_status_pub = orb_advertise(telemetry_status_orb_id[_mavlink->get_channel()], &tstatus);
 
 		} else {
@@ -974,7 +974,7 @@ MavlinkReceiver::handle_message_manual_control(mavlink_message_t *msg)
 
 	// warnx("pitch: %.2f, roll: %.2f, yaw: %.2f, throttle: %.2f", (double)manual.x, (double)manual.y, (double)manual.r, (double)manual.z);
 
-	if (_manual_pub < 0) {
+	if (_manual_pub == 0) {
 		_manual_pub = orb_advertise(ORB_ID(manual_control_setpoint), &manual);
 
 	} else {
@@ -1001,7 +1001,7 @@ MavlinkReceiver::handle_message_heartbeat(mavlink_message_t *msg)
 			tstatus.timestamp = hrt_absolute_time();
 			tstatus.heartbeat_time = tstatus.timestamp;
 
-			if (_telemetry_status_pub < 0) {
+			if (_telemetry_status_pub == 0) {
 				_telemetry_status_pub = orb_advertise(telemetry_status_orb_id[_mavlink->get_channel()], &tstatus);
 
 			} else {
@@ -1105,7 +1105,7 @@ MavlinkReceiver::handle_message_timesync(mavlink_message_t *msg)
 
 	tsync_offset.offset_ns = _time_offset ;
 
-	if (_time_offset_pub < 0) {
+	if (_time_offset_pub == 0) {
 		_time_offset_pub = orb_advertise(ORB_ID(time_offset), &tsync_offset);
 
 	} else {
@@ -1135,7 +1135,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		airspeed.indicated_airspeed_m_s = ias;
 		airspeed.true_airspeed_m_s = tas;
 
-		if (_airspeed_pub < 0) {
+		if (_airspeed_pub == 0) {
 			_airspeed_pub = orb_advertise(ORB_ID(airspeed), &airspeed);
 
 		} else {
@@ -1157,7 +1157,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		gyro.z = imu.zgyro;
 		gyro.temperature = imu.temperature;
 
-		if (_gyro_pub < 0) {
+		if (_gyro_pub == 0) {
 			_gyro_pub = orb_advertise(ORB_ID(sensor_gyro), &gyro);
 
 		} else {
@@ -1179,7 +1179,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		accel.z = imu.zacc;
 		accel.temperature = imu.temperature;
 
-		if (_accel_pub < 0) {
+		if (_accel_pub == 0) {
 			_accel_pub = orb_advertise(ORB_ID(sensor_accel), &accel);
 
 		} else {
@@ -1200,7 +1200,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		mag.y = imu.ymag;
 		mag.z = imu.zmag;
 
-		if (_mag_pub < 0) {
+		if (_mag_pub == 0) {
 			/* publish to the first mag topic */
 			_mag_pub = orb_advertise(ORB_ID(sensor_mag), &mag);
 
@@ -1219,7 +1219,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		baro.altitude = imu.pressure_alt;
 		baro.temperature = imu.temperature;
 
-		if (_baro_pub < 0) {
+		if (_baro_pub == 0) {
 			_baro_pub = orb_advertise(ORB_ID(sensor_baro), &baro);
 
 		} else {
@@ -1275,7 +1275,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		hil_sensors.differential_pressure_timestamp = timestamp;
 
 		/* publish combined sensor topic */
-		if (_sensors_pub < 0) {
+		if (_sensors_pub == 0) {
 			_sensors_pub = orb_advertise(ORB_ID(sensor_combined), &hil_sensors);
 
 		} else {
@@ -1294,7 +1294,7 @@ MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
 		hil_battery_status.current_a = 10.0f;
 		hil_battery_status.discharged_mah = -1.0f;
 
-		if (_battery_pub < 0) {
+		if (_battery_pub == 0) {
 			_battery_pub = orb_advertise(ORB_ID(battery_status), &hil_battery_status);
 
 		} else {
@@ -1348,7 +1348,7 @@ MavlinkReceiver::handle_message_hil_gps(mavlink_message_t *msg)
 	hil_gps.fix_type = gps.fix_type;
 	hil_gps.satellites_used = gps.satellites_visible;  //TODO: rename mavlink_hil_gps_t sats visible to used?
 
-	if (_gps_pub < 0) {
+	if (_gps_pub == 0) {
 		_gps_pub = orb_advertise(ORB_ID(vehicle_gps_position), &hil_gps);
 
 	} else {
@@ -1373,7 +1373,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		airspeed.indicated_airspeed_m_s = hil_state.ind_airspeed * 1e-2f;
 		airspeed.true_airspeed_m_s = hil_state.true_airspeed * 1e-2f;
 
-		if (_airspeed_pub < 0) {
+		if (_airspeed_pub == 0) {
 			_airspeed_pub = orb_advertise(ORB_ID(airspeed), &airspeed);
 
 		} else {
@@ -1406,7 +1406,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		hil_attitude.pitchspeed = hil_state.pitchspeed;
 		hil_attitude.yawspeed = hil_state.yawspeed;
 
-		if (_attitude_pub < 0) {
+		if (_attitude_pub == 0) {
 			_attitude_pub = orb_advertise(ORB_ID(vehicle_attitude), &hil_attitude);
 
 		} else {
@@ -1430,7 +1430,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		hil_global_pos.eph = 2.0f;
 		hil_global_pos.epv = 4.0f;
 
-		if (_global_pos_pub < 0) {
+		if (_global_pos_pub == 0) {
 			_global_pos_pub = orb_advertise(ORB_ID(vehicle_global_position), &hil_global_pos);
 
 		} else {
@@ -1471,7 +1471,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		hil_local_pos.xy_global = true;
 		hil_local_pos.z_global = true;
 
-		if (_local_pos_pub < 0) {
+		if (_local_pos_pub == 0) {
 			_local_pos_pub = orb_advertise(ORB_ID(vehicle_local_position), &hil_local_pos);
 
 		} else {
@@ -1486,7 +1486,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 			hil_land_detector.landed = landed;
 			hil_land_detector.timestamp = hrt_absolute_time();
 
-			if (_land_detector_pub < 0) {
+			if (_land_detector_pub == 0) {
 				_land_detector_pub = orb_advertise(ORB_ID(vehicle_land_detected), &hil_land_detector);
 
 			} else {
@@ -1509,7 +1509,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		accel.z = hil_state.zacc;
 		accel.temperature = 25.0f;
 
-		if (_accel_pub < 0) {
+		if (_accel_pub == 0) {
 			_accel_pub = orb_advertise(ORB_ID(sensor_accel), &accel);
 
 		} else {
@@ -1528,7 +1528,7 @@ MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
 		hil_battery_status.current_a = 10.0f;
 		hil_battery_status.discharged_mah = -1.0f;
 
-		if (_battery_pub < 0) {
+		if (_battery_pub == 0) {
 			_battery_pub = orb_advertise(ORB_ID(battery_status), &hil_battery_status);
 
 		} else {
diff --git a/src/modules/mc_att_control/mc_att_control_main.cpp b/src/modules/mc_att_control/mc_att_control_main.cpp
index d65694224b..965c746960 100644
--- a/src/modules/mc_att_control/mc_att_control_main.cpp
+++ b/src/modules/mc_att_control/mc_att_control_main.cpp
@@ -314,10 +314,10 @@ MulticopterAttitudeControl::MulticopterAttitudeControl() :
 	_vehicle_status_sub(-1),
 
 /* publications */
-	_att_sp_pub(-1),
-	_v_rates_sp_pub(-1),
-	_actuators_0_pub(-1),
-	_controller_status_pub(-1),
+	_att_sp_pub(0),
+	_v_rates_sp_pub(0),
+	_actuators_0_pub(0),
+	_controller_status_pub(0),
 	_rates_sp_id(0),
 	_actuators_id(0),
 
diff --git a/src/modules/mc_pos_control/mc_pos_control_main.cpp b/src/modules/mc_pos_control/mc_pos_control_main.cpp
index b6ad4fd547..c77c33a849 100644
--- a/src/modules/mc_pos_control/mc_pos_control_main.cpp
+++ b/src/modules/mc_pos_control/mc_pos_control_main.cpp
@@ -307,9 +307,9 @@ MulticopterPositionControl::MulticopterPositionControl() :
 	_global_vel_sp_sub(-1),
 
 /* publications */
-	_att_sp_pub(-1),
-	_local_pos_sp_pub(-1),
-	_global_vel_sp_pub(-1),
+	_att_sp_pub(0),
+	_local_pos_sp_pub(0),
+	_global_vel_sp_pub(0),
 
 	_ref_alt(0.0f),
 	_ref_timestamp(0),
diff --git a/src/modules/navigator/geofence.cpp b/src/modules/navigator/geofence.cpp
index 70d93b953d..993b059a94 100644
--- a/src/modules/navigator/geofence.cpp
+++ b/src/modules/navigator/geofence.cpp
@@ -69,7 +69,7 @@ static const int ERROR = -1;
 
 Geofence::Geofence() :
 	SuperBlock(NULL, "GF"),
-	_fence_pub(-1),
+	_fence_pub(0),
 	_home_pos{},
 	_home_pos_set(false),
 	_last_horizontal_range_warning(0),
@@ -317,7 +317,7 @@ Geofence::addPoint(int argc, char *argv[])
 void
 Geofence::publishFence(unsigned vertices)
 {
-	if (_fence_pub == -1) {
+	if (_fence_pub == 0) {
 		_fence_pub = orb_advertise(ORB_ID(fence), &vertices);
 
 	} else {
diff --git a/src/modules/navigator/navigator_main.cpp b/src/modules/navigator/navigator_main.cpp
index 4971d6bc29..e0083d50d5 100644
--- a/src/modules/navigator/navigator_main.cpp
+++ b/src/modules/navigator/navigator_main.cpp
@@ -108,10 +108,10 @@ Navigator::Navigator() :
 	_onboard_mission_sub(-1),
 	_offboard_mission_sub(-1),
 	_param_update_sub(-1),
-	_pos_sp_triplet_pub(-1),
-	_mission_result_pub(-1),
-	_geofence_result_pub(-1),
-	_att_sp_pub(-1),
+	_pos_sp_triplet_pub(0),
+	_mission_result_pub(0),
+	_geofence_result_pub(0),
+	_att_sp_pub(0),
 	_vstatus{},
 	_control_mode{},
 	_global_pos{},
diff --git a/src/modules/position_estimator_inav/position_estimator_inav_main.c b/src/modules/position_estimator_inav/position_estimator_inav_main.c
index 9dc7999099..4cadd638bc 100644
--- a/src/modules/position_estimator_inav/position_estimator_inav_main.c
+++ b/src/modules/position_estimator_inav/position_estimator_inav_main.c
@@ -343,7 +343,7 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 
 	/* advertise */
 	orb_advert_t vehicle_local_position_pub = orb_advertise(ORB_ID(vehicle_local_position), &local_pos);
-	orb_advert_t vehicle_global_position_pub = -1;
+	orb_advert_t vehicle_global_position_pub = 0;
 
 	struct position_estimator_inav_params params;
 	struct position_estimator_inav_param_handles pos_inav_param_handles;
@@ -1158,7 +1158,7 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 				global_pos.eph = eph;
 				global_pos.epv = epv;
 
-				if (vehicle_global_position_pub < 0) {
+				if (vehicle_global_position_pub == 0) {
 					vehicle_global_position_pub = orb_advertise(ORB_ID(vehicle_global_position), &global_pos);
 
 				} else {
diff --git a/src/modules/sdlog2/sdlog2.c b/src/modules/sdlog2/sdlog2.c
index 5ccadde57f..8bc885eb8c 100644
--- a/src/modules/sdlog2/sdlog2.c
+++ b/src/modules/sdlog2/sdlog2.c
@@ -373,8 +373,7 @@ int sdlog2_main(int argc, char *argv[])
 		cmd.param1 = -1;
 		cmd.param2 = -1;
 		cmd.param3 = 1;
-		int fd = orb_advertise(ORB_ID(vehicle_command), &cmd);
-		close(fd);
+		orb_advertise(ORB_ID(vehicle_command), &cmd);
 		return 0;
 	}
 
@@ -384,8 +383,7 @@ int sdlog2_main(int argc, char *argv[])
 		cmd.param1 = -1;
 		cmd.param2 = -1;
 		cmd.param3 = 2;
-		int fd = orb_advertise(ORB_ID(vehicle_command), &cmd);
-		close(fd);
+		orb_advertise(ORB_ID(vehicle_command), &cmd);
 		return 0;
 	}
 
diff --git a/src/modules/sensors/sensors.cpp b/src/modules/sensors/sensors.cpp
index cf1f51c9dd..83ef0ff4ee 100644
--- a/src/modules/sensors/sensors.cpp
+++ b/src/modules/sensors/sensors.cpp
@@ -517,13 +517,13 @@ Sensors::Sensors() :
 	_manual_control_sub(-1),
 
 	/* publications */
-	_sensor_pub(-1),
-	_manual_control_pub(-1),
-	_actuator_group_3_pub(-1),
-	_rc_pub(-1),
-	_battery_pub(-1),
-	_airspeed_pub(-1),
-	_diff_pres_pub(-1),
+	_sensor_pub(0),
+	_manual_control_pub(0),
+	_actuator_group_3_pub(0),
+	_rc_pub(0),
+	_battery_pub(0),
+	_airspeed_pub(0),
+	_diff_pres_pub(0),
 
 	/* performance counters */
 	_loop_perf(perf_alloc(PC_ELAPSED, "sensor task update")),
diff --git a/src/modules/simulator/simulator_mavlink.cpp b/src/modules/simulator/simulator_mavlink.cpp
index ed4a6343fe..837208eaff 100644
--- a/src/modules/simulator/simulator_mavlink.cpp
+++ b/src/modules/simulator/simulator_mavlink.cpp
@@ -157,7 +157,7 @@ void Simulator::handle_message(mavlink_message_t *msg) {
 			fill_sensors_from_imu_msg(&_sensor, &imu);
 
 			// publish message
-			if(_sensor_combined_pub < 0) {
+			if(_sensor_combined_pub == 0) {
 				_sensor_combined_pub = orb_advertise(ORB_ID(sensor_combined), &_sensor);
 			} else {
 				orb_publish(ORB_ID(sensor_combined), _sensor_combined_pub, &_sensor);
@@ -171,7 +171,7 @@ void Simulator::handle_message(mavlink_message_t *msg) {
 			fill_manual_control_sp_msg(&_manual_control_sp, &man_ctrl_sp);
 
 			// publish message
-			if(_manual_control_sp_pub < 0) {
+			if(_manual_control_sp_pub == 0) {
 				_manual_control_sp_pub = orb_advertise(ORB_ID(manual_control_setpoint), &_manual_control_sp);
 			} else {
 				orb_publish(ORB_ID(manual_control_setpoint), _manual_control_sp_pub, &_manual_control_sp);
diff --git a/src/modules/systemlib/param/param.c b/src/modules/systemlib/param/param.c
index 09e9e88870..f5af2e27df 100644
--- a/src/modules/systemlib/param/param.c
+++ b/src/modules/systemlib/param/param.c
@@ -130,7 +130,7 @@ const UT_icd	param_icd = {sizeof(struct param_wbuf_s), NULL, NULL, NULL};
 ORB_DEFINE(parameter_update, struct parameter_update_s);
 
 /** parameter update topic handle */
-static orb_advert_t param_topic = -1;
+static orb_advert_t param_topic = 0;
 
 static void param_set_used_internal(param_t param);
 
@@ -233,7 +233,7 @@ param_notify_changes(void)
 	 * If we don't have a handle to our topic, create one now; otherwise
 	 * just publish.
 	 */
-	if (param_topic == -1) {
+	if (param_topic == 0) {
 		param_topic = orb_advertise(ORB_ID(parameter_update), &pup);
 
 	} else {
diff --git a/src/modules/uORB/uORB.h b/src/modules/uORB/uORB.h
index a8b19d91f9..63571488b8 100644
--- a/src/modules/uORB/uORB.h
+++ b/src/modules/uORB/uORB.h
@@ -135,7 +135,7 @@ __BEGIN_DECLS
  * a file-descriptor-based handle would not otherwise be in scope for the
  * publisher.
  */
-typedef intptr_t	orb_advert_t;
+typedef uintptr_t	orb_advert_t;
 
 /**
  * Advertise as the publisher of a topic.
diff --git a/src/modules/uORB/uORBManager_nuttx.cpp b/src/modules/uORB/uORBManager_nuttx.cpp
index 85746c0c27..479103fe7d 100644
--- a/src/modules/uORB/uORBManager_nuttx.cpp
+++ b/src/modules/uORB/uORBManager_nuttx.cpp
@@ -89,18 +89,18 @@ orb_advert_t uORB::Manager::orb_advertise_multi(const struct orb_metadata *meta,
   /* open the node as an advertiser */
   fd = node_open(PUBSUB, meta, data, true, instance, priority);
   if (fd == ERROR)
-    return ERROR;
+    return 0;
 
   /* get the advertiser handle and close the node */
   result = ioctl(fd, ORBIOCGADVERTISER, (unsigned long)&advertiser);
   close(fd);
   if (result == ERROR)
-    return ERROR;
+    return 0;
 
   /* the advertiser must perform an initial publish to initialise the object */
   result = orb_publish(meta, advertiser, data);
   if (result == ERROR)
-    return ERROR;
+    return 0;
 
   return advertiser;
 }
diff --git a/src/modules/uORB/uORBManager_posix.cpp b/src/modules/uORB/uORBManager_posix.cpp
index a9dad24dcd..bcb36470fe 100644
--- a/src/modules/uORB/uORBManager_posix.cpp
+++ b/src/modules/uORB/uORBManager_posix.cpp
@@ -94,7 +94,7 @@ orb_advert_t uORB::Manager::orb_advertise_multi(const struct orb_metadata *meta,
   fd = node_open(PUBSUB, meta, data, true, instance, priority);
   if (fd == ERROR) {
     warnx("node_open as advertiser failed.");
-    return ERROR;
+    return 0;
   }
 
   /* get the advertiser handle and close the node */
@@ -102,14 +102,14 @@ orb_advert_t uORB::Manager::orb_advertise_multi(const struct orb_metadata *meta,
   px4_close(fd);
   if (result == ERROR) {
     warnx("px4_ioctl ORBIOCGADVERTISER  failed. fd = %d", fd);
-    return ERROR;
+    return 0;
   }
 
   /* the advertiser must perform an initial publish to initialise the object */
   result = orb_publish(meta, advertiser, data);
   if (result == ERROR) {
     warnx("orb_publish failed");
-    return ERROR;
+    return 0;
   }
 
   return advertiser;
diff --git a/src/modules/uORB/uORBTest_UnitTest.cpp b/src/modules/uORB/uORBTest_UnitTest.cpp
index 722f538976..edb7994e8f 100644
--- a/src/modules/uORB/uORBTest_UnitTest.cpp
+++ b/src/modules/uORB/uORBTest_UnitTest.cpp
@@ -137,16 +137,17 @@ int uORBTest::UnitTest::pubsublatency_main(void)
 int uORBTest::UnitTest::test()
 {
   struct orb_test t, u;
-  int pfd, sfd;
+  int sfd;
+  orb_advert_t ptopic;
   bool updated;
 
   t.val = 0;
-  pfd = orb_advertise(ORB_ID(orb_test), &t);
+  ptopic = orb_advertise(ORB_ID(orb_test), &t);
 
-  if (pfd < 0)
+  if (ptopic == 0)
     return test_fail("advertise failed: %d", errno);
 
-  test_note("publish handle 0x%08x", pfd);
+  test_note("publish handle 0x%08x", ptopic);
   sfd = orb_subscribe(ORB_ID(orb_test));
 
   if (sfd < 0)
@@ -170,7 +171,7 @@ int uORBTest::UnitTest::test()
   t.val = 2;
   test_note("try publish");
 
-  if (PX4_OK != orb_publish(ORB_ID(orb_test), pfd, &t))
+  if (PX4_OK != orb_publish(ORB_ID(orb_test), ptopic, &t))
     return test_fail("publish failed");
 
   if (PX4_OK != orb_check(sfd, &updated))
@@ -186,7 +187,6 @@ int uORBTest::UnitTest::test()
     return test_fail("copy(2) mismatch: %d expected %d", u.val, t.val);
 
   orb_unsubscribe(sfd);
-  close(pfd);
 
   /* this routine tests the multi-topic support */
   test_note("try multi-topic support");
@@ -197,7 +197,7 @@ int uORBTest::UnitTest::test()
   test_note("advertised");
 
   int instance1;
-  int pfd1 = orb_advertise_multi(ORB_ID(orb_multitest), &t, &instance1, ORB_PRIO_MIN);
+  orb_advert_t pfd1 = orb_advertise_multi(ORB_ID(orb_multitest), &t, &instance1, ORB_PRIO_MIN);
 
   if (instance0 != 0)
     return test_fail("mult. id0: %d", instance0);
diff --git a/src/modules/uORB/uORBTest_UnitTest.hpp b/src/modules/uORB/uORBTest_UnitTest.hpp
index f19c95451d..93399f734f 100644
--- a/src/modules/uORB/uORBTest_UnitTest.hpp
+++ b/src/modules/uORB/uORBTest_UnitTest.hpp
@@ -98,7 +98,7 @@ int uORBTest::UnitTest::latency_test(orb_id_t T, bool print)
   t.val = 308;
   t.time = hrt_absolute_time();
 
-  int pfd0 = orb_advertise(T, &t);
+  orb_advert_t pfd0 = orb_advertise(T, &t);
 
   char * const args[1] = { NULL };
 
@@ -128,8 +128,6 @@ int uORBTest::UnitTest::latency_test(orb_id_t T, bool print)
     usleep(1000);
   }
 
-  px4_close(pfd0);
-
   if (pubsub_task < 0) {
     return test_fail("failed launching task");
   }
diff --git a/src/modules/uavcan/sensors/gnss.cpp b/src/modules/uavcan/sensors/gnss.cpp
index 3ae07367fa..cd8b52862e 100644
--- a/src/modules/uavcan/sensors/gnss.cpp
+++ b/src/modules/uavcan/sensors/gnss.cpp
@@ -48,7 +48,7 @@ const char *const UavcanGnssBridge::NAME = "gnss";
 UavcanGnssBridge::UavcanGnssBridge(uavcan::INode &node) :
 _node(node),
 _sub_fix(node),
-_report_pub(-1)
+_report_pub(0)
 {
 }
 
diff --git a/src/modules/uavcan/sensors/sensor_bridge.cpp b/src/modules/uavcan/sensors/sensor_bridge.cpp
index b370764440..419f671eb3 100644
--- a/src/modules/uavcan/sensors/sensor_bridge.cpp
+++ b/src/modules/uavcan/sensors/sensor_bridge.cpp
@@ -119,7 +119,7 @@ void UavcanCDevSensorBridgeBase::publish(const int node_id, const void *report)
 		channel->class_instance = class_instance;
 
 		channel->orb_advert = orb_advertise_multi(_orb_topic, report, &channel->orb_instance, ORB_PRIO_HIGH);
-		if (channel->orb_advert < 0) {
+		if (channel->orb_advert == 0) {
 			log("ADVERTISE FAILED");
 			(void)unregister_class_devname(_class_devname, class_instance);
 			*channel = Channel();
diff --git a/src/modules/vtol_att_control/vtol_att_control_main.cpp b/src/modules/vtol_att_control/vtol_att_control_main.cpp
index 11aa88a5f3..bbb1037fbd 100644
--- a/src/modules/vtol_att_control/vtol_att_control_main.cpp
+++ b/src/modules/vtol_att_control/vtol_att_control_main.cpp
@@ -230,10 +230,10 @@ VtolAttitudeControl::VtolAttitudeControl() :
 	_battery_status_sub(-1),
 
 	//init publication handlers
-	_actuators_0_pub(-1),
-	_actuators_1_pub(-1),
-	_vtol_vehicle_status_pub(-1),
-	_v_rates_sp_pub(-1),
+	_actuators_0_pub(0),
+	_actuators_1_pub(0),
+	_vtol_vehicle_status_pub(0),
+	_v_rates_sp_pub(0),
 
 	_loop_perf(perf_alloc(PC_ELAPSED, "vtol_att_control")),
 	_nonfinite_input_perf(perf_alloc(PC_COUNT, "vtol att control nonfinite input"))
diff --git a/src/platforms/posix/drivers/accelsim/accelsim.cpp b/src/platforms/posix/drivers/accelsim/accelsim.cpp
index c68371c315..9722b79a56 100644
--- a/src/platforms/posix/drivers/accelsim/accelsim.cpp
+++ b/src/platforms/posix/drivers/accelsim/accelsim.cpp
@@ -369,7 +369,7 @@ ACCELSIM::ACCELSIM(const char* path, enum Rotation rotation) :
 	_mag_range_ga(0.0f),
 	_mag_range_scale(0.0f),
 	_mag_samplerate(0),
-	_accel_topic(-1),
+	_accel_topic(0),
 	_accel_orb_class_instance(-1),
 	_accel_class_instance(-1),
 	_accel_read(0),
@@ -496,7 +496,7 @@ ACCELSIM::init()
 	_accel_topic = orb_advertise_multi(ORB_ID(sensor_accel), &arp,
 		&_accel_orb_class_instance, ORB_PRIO_DEFAULT);
 
-	if (_accel_topic == (orb_advert_t)(-1)) {
+	if (_accel_topic == 0) {
 		PX4_WARN("ADVERT ERR");
 	}
 
@@ -1077,7 +1077,7 @@ ACCELSIM::measure()
 
 		// The first call to measure() is from init() and _accel_topic is not
 		// yet initialized
-		if (_accel_topic != (orb_advert_t)(-1)) {
+		if (_accel_topic != 0) {
 			orb_publish(ORB_ID(sensor_accel), _accel_topic, &accel_report);
 		}
 	}
diff --git a/src/platforms/posix/drivers/airspeedsim/airspeedsim.cpp b/src/platforms/posix/drivers/airspeedsim/airspeedsim.cpp
index d0cf702a77..8cea970885 100644
--- a/src/platforms/posix/drivers/airspeedsim/airspeedsim.cpp
+++ b/src/platforms/posix/drivers/airspeedsim/airspeedsim.cpp
@@ -83,8 +83,8 @@ Airspeed::Airspeed(int bus, int address, unsigned conversion_interval, const cha
 	_measure_ticks(0),
 	_collect_phase(false),
 	_diff_pres_offset(0.0f),
-	_airspeed_pub(-1),
-	_subsys_pub(-1),
+	_airspeed_pub(0),
+	_subsys_pub(0),
 	_class_instance(-1),
 	_conversion_interval(conversion_interval),
 	_sample_perf(perf_alloc(PC_ELAPSED, "airspeed_read")),
@@ -143,7 +143,7 @@ Airspeed::init()
 		/* measurement will have generated a report, publish */
 		_airspeed_pub = orb_advertise(ORB_ID(differential_pressure), &arp);
 
-		if (_airspeed_pub < 0)
+		if (_airspeed_pub == 0)
 			PX4_WARN("uORB started?");
 	}
 
diff --git a/src/platforms/posix/drivers/barosim/baro.cpp b/src/platforms/posix/drivers/barosim/baro.cpp
index dbabec9c4b..6492c9606b 100644
--- a/src/platforms/posix/drivers/barosim/baro.cpp
+++ b/src/platforms/posix/drivers/barosim/baro.cpp
@@ -213,7 +213,7 @@ BAROSIM::BAROSIM(device::Device *interface, barosim::prom_u &prom_buf, const cha
 	_OFF(0),
 	_SENS(0),
 	_msl_pressure(101325),
-	_baro_topic(-1),
+	_baro_topic(0),
 	_orb_class_instance(-1),
 	_class_instance(-1),
 	_sample_perf(perf_alloc(PC_ELAPSED, "barosim_read")),
@@ -315,7 +315,7 @@ BAROSIM::init()
 		_baro_topic = orb_advertise_multi(ORB_ID(sensor_baro), &brp,
 				&_orb_class_instance, (is_external()) ? ORB_PRIO_HIGH : ORB_PRIO_DEFAULT);
 
-		if (_baro_topic == (orb_advert_t)(-1)) {
+		if (_baro_topic == 0) {
 			PX4_ERR("failed to create sensor_baro publication");
 		}
 		//PX4_WARN("sensor_baro publication %ld", _baro_topic);
@@ -722,7 +722,7 @@ BAROSIM::collect()
 
 		/* publish it */
 		if (!(_pub_blocked)) {
-			if (_baro_topic != (orb_advert_t)(-1)) {
+			if (_baro_topic != 0) {
 				/* publish it */
 				orb_publish(ORB_ID(sensor_baro), _baro_topic, &report);
 			}
diff --git a/src/platforms/posix/drivers/gyrosim/gyrosim.cpp b/src/platforms/posix/drivers/gyrosim/gyrosim.cpp
index 80cef4c867..619c74c6b3 100644
--- a/src/platforms/posix/drivers/gyrosim/gyrosim.cpp
+++ b/src/platforms/posix/drivers/gyrosim/gyrosim.cpp
@@ -472,7 +472,7 @@ GYROSIM::GYROSIM(const char *path_accel, const char *path_gyro, enum Rotation ro
 	_accel_scale{},
 	_accel_range_scale(0.0f),
 	_accel_range_m_s2(0.0f),
-	_accel_topic(-1),
+	_accel_topic(0),
 	_accel_orb_class_instance(-1),
 	_accel_class_instance(-1),
 	_gyro_reports(nullptr),
@@ -624,7 +624,7 @@ GYROSIM::init()
 	_accel_topic = orb_advertise_multi(ORB_ID(sensor_accel), &arp,
 		&_accel_orb_class_instance, ORB_PRIO_HIGH);
 
-	if (_accel_topic < 0) {
+	if (_accel_topic == 0) {
 		PX4_WARN("ADVERT FAIL");
 	}
 
@@ -636,7 +636,7 @@ GYROSIM::init()
 	_gyro->_gyro_topic = orb_advertise_multi(ORB_ID(sensor_gyro), &grp,
 		&_gyro->_gyro_orb_class_instance, ORB_PRIO_HIGH);
 
-	if (_gyro->_gyro_topic < 0) {
+	if (_gyro->_gyro_topic == 0) {
 		PX4_WARN("ADVERT FAIL");
 	}
 
@@ -1547,7 +1547,7 @@ GYROSIM::print_registers()
 GYROSIM_gyro::GYROSIM_gyro(GYROSIM *parent, const char *path) :
 	VDev("GYROSIM_gyro", path),
 	_parent(parent),
-	_gyro_topic(-1),
+	_gyro_topic(0),
 	_gyro_orb_class_instance(-1),
 	_gyro_class_instance(-1)
 {
diff --git a/src/systemcmds/motor_test/motor_test.c b/src/systemcmds/motor_test/motor_test.c
index b77730ef16..d5def7056b 100644
--- a/src/systemcmds/motor_test/motor_test.c
+++ b/src/systemcmds/motor_test/motor_test.c
@@ -59,7 +59,7 @@ __EXPORT int motor_test_main(int argc, char *argv[]);
 static void motor_test(unsigned channel, float value);
 static void usage(const char *reason);
 
-static orb_advert_t _test_motor_pub;
+static orb_advert_t _test_motor_pub = 0;
 
 void motor_test(unsigned channel, float value)
 {