diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index 9b748c384f..1cf020240a 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -709,7 +709,7 @@ AP_InertialSensor::detect_backends(void)
 #elif HAL_INS_DEFAULT == HAL_INS_BH
     _add_backend(AP_InertialSensor_Invensense::probe(*this, hal.i2c_mgr->get_device(HAL_INS_MPU60x0_I2C_BUS, HAL_INS_MPU60x0_I2C_ADDR)));
     _add_backend(AP_InertialSensor_Invensense::probe(*this, hal.spi->get_device(HAL_INS_MPU9250_NAME)));
-#elif HAL_INS_DEFAULT == HAL_INS_PX4 || HAL_INS_DEFAULT == HAL_INS_VRBRAIN
+#elif defined(HAL_CHIBIOS_ARCH_FMUV3) || HAL_INS_DEFAULT == HAL_INS_PX4 || HAL_INS_DEFAULT == HAL_INS_VRBRAIN
 
     switch (AP_BoardConfig::get_board_type()) {
     case AP_BoardConfig::PX4_BOARD_PX4V1:
@@ -778,8 +778,10 @@ AP_InertialSensor::detect_backends(void)
     default:
         break;
     }
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
     // also add any PX4 backends (eg. canbus sensors)
     _add_backend(AP_InertialSensor_PX4::detect(*this));
+#endif
 #elif HAL_INS_DEFAULT == HAL_INS_MPU9250_SPI && defined(HAL_INS_DEFAULT_ROTATION)
     _add_backend(AP_InertialSensor_Invensense::probe(*this, hal.spi->get_device(HAL_INS_MPU9250_NAME), HAL_INS_DEFAULT_ROTATION));
 #elif HAL_INS_DEFAULT == HAL_INS_MPU9250_SPI