diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index b50cf79021..1d81340480 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -1078,6 +1078,7 @@ void AP_InertialSensor::set_accel(uint8_t instance, const Vector3f &accel)
 {
     if (instance < INS_MAX_INSTANCES) {
         _accel[instance] = accel;
+        _accel_healthy[instance] = true;
     }
 }
 
@@ -1085,6 +1086,7 @@ void AP_InertialSensor::set_gyro(uint8_t instance, const Vector3f &gyro)
 {
     if (instance < INS_MAX_INSTANCES) {
         _gyro[instance] = gyro;
+        _gyro_healthy[instance] = true;
     }
 }
 
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
index e0070d7616..50bfb4d6b6 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
@@ -33,6 +33,7 @@ bool AP_InertialSensor_HIL::_init_sensor(void)
     _imu.register_accel();
 
     _product_id = AP_PRODUCT_ID_NONE;
+    _imu.set_hil_mode();
 
     return true;
 }