diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Stub.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Stub.cpp
index 629e7a7ee9..7e90200902 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Stub.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Stub.cpp
@@ -55,3 +55,7 @@ void AP_InertialSensor_Stub::reset_sample_time() {
 float AP_InertialSensor_Stub::get_gyro_drift_rate(void) {
     return 0.0;
 }
+uint16_t AP_InertialSensor_Stub::num_samples_available()
+{
+    return 1;
+}
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Stub.h b/libraries/AP_InertialSensor/AP_InertialSensor_Stub.h
index eeda9cd35d..6fd58a26b6 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Stub.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Stub.h
@@ -34,6 +34,7 @@ public:
     uint32_t        sample_time();
     void            reset_sample_time();
     float           get_gyro_drift_rate();
+    uint16_t        num_samples_available();
 };
 
 #endif // __AP_INERTIAL_SENSOR_STUB_H__