diff --git a/src/drivers/boards/px4fmu-v4/board_config.h b/src/drivers/boards/px4fmu-v4/board_config.h
index 65d0aa4532..f5ba9bb8df 100644
--- a/src/drivers/boards/px4fmu-v4/board_config.h
+++ b/src/drivers/boards/px4fmu-v4/board_config.h
@@ -245,7 +245,7 @@ __BEGIN_DECLS
 #define SPEKTRUM_RX_AS_UART()		stm32_configgpio(GPIO_USART1_RX)
 
 // FMUv4 has a separate GPIO for serial RC output
-#define GPIO_RC_OUT					(GPIO_OUTPUT|GPIO_PUSHPULL|GPIO_SPEED_2MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTC|GPIO_PIN6)
+#define GPIO_RC_OUT			(GPIO_OUTPUT|GPIO_PUSHPULL|GPIO_SPEED_2MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTC|GPIO_PIN6)
 #define SPEKTRUM_RX_AS_GPIO()		stm32_configgpio(GPIO_RC_OUT)
 #define SPEKTRUM_RX_HIGH(_s)		stm32_gpiowrite(GPIO_RC_OUT, (_s))
 
diff --git a/src/drivers/px4fmu/fmu.cpp b/src/drivers/px4fmu/fmu.cpp
index 8d72c42bd0..d8e156351b 100644
--- a/src/drivers/px4fmu/fmu.cpp
+++ b/src/drivers/px4fmu/fmu.cpp
@@ -227,6 +227,8 @@ private:
 			unsigned frame_drops, int rssi);
 	void dsm_bind_ioctl(int dsmMode);
 	void set_rc_scan_state(RC_SCAN _rc_scan_state);
+	void rc_io_invert();
+	void rc_io_invert(bool invert);
 };
 
 const PX4FMU::GPIOConfig PX4FMU::_gpio_tab[] = {
@@ -678,6 +680,16 @@ void PX4FMU::set_rc_scan_state(RC_SCAN newState)
 	_rc_scan_state = newState;
 }
 
+void PX4FMU::rc_io_invert(bool invert)
+{
+	INVERT_RC_INPUT(invert);
+
+	if (!invert) {
+		// set FMU_RC_OUTPUT high to pull RC_INPUT up
+		stm32_gpiowrite(GPIO_RC_OUT, 1);
+	}
+}
+
 void
 PX4FMU::cycle()
 {
@@ -914,7 +926,7 @@ PX4FMU::cycle()
 			_rc_scan_begin = now;
 			// Configure serial port for SBUS
 			sbus_config(_rcs_fd, false);
-			INVERT_RC_INPUT(true);
+			rc_io_invert(true);
 
 		} else if (now - _rc_scan_last_lock < rc_scan_max
 			   || now - _rc_scan_begin < rc_scan_max) {
@@ -945,7 +957,7 @@ PX4FMU::cycle()
 			_rc_scan_begin = now;
 //			// Configure serial port for DSM
 			dsm_config(_rcs_fd);
-			INVERT_RC_INPUT(false);
+			rc_io_invert(false);
 
 		} else if (now - _rc_scan_last_lock < rc_scan_max
 			   || now - _rc_scan_begin < rc_scan_max) {
@@ -976,7 +988,7 @@ PX4FMU::cycle()
 			_rc_scan_begin = now;
 //			// Configure serial port for DSM
 			dsm_config(_rcs_fd);
-			INVERT_RC_INPUT(false);
+			rc_io_invert(false);
 
 		} else if (now - _rc_scan_last_lock < rc_scan_max
 			   || now - _rc_scan_begin < rc_scan_max) {
@@ -1015,7 +1027,7 @@ PX4FMU::cycle()
 			_rc_scan_begin = now;
 //			// Configure serial port for DSM
 			dsm_config(_rcs_fd);
-			INVERT_RC_INPUT(false);
+			rc_io_invert(false);
 
 		} else if (now - _rc_scan_last_lock < rc_scan_max
 			   || now - _rc_scan_begin < rc_scan_max) {
@@ -1057,6 +1069,7 @@ PX4FMU::cycle()
 			_rc_scan_begin = now;
 			// Configure timer input pin for CPPM
 			stm32_configgpio(GPIO_PPM_IN);
+			rc_io_invert(false);
 
 		} else if (now - _rc_scan_last_lock < rc_scan_max
 			   || now - _rc_scan_begin < rc_scan_max) {