diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
index b58420b7a9..ccd6a67c41 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
@@ -100,10 +100,13 @@ AP_InertialSensor_MPU6000::AP_InertialSensor_MPU6000( uint8_t cs_pin )
   _accel.y = 0;
   _accel.z = 0;
   _temp = 0;
+  _initialised = 0;
 }
 
 void AP_InertialSensor_MPU6000::init( AP_PeriodicProcess * scheduler )
 {
+    if (_initialised) return;
+    _initialised = 1;
     hardware_init();
     scheduler->register_process( &AP_InertialSensor_MPU6000::read );
 }
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.h b/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.h
index 844719b232..b6044c36d5 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.h
@@ -64,6 +64,9 @@ class AP_InertialSensor_MPU6000 : public AP_InertialSensor
 
   /* TODO deprecate _cs_pin */
   static uint8_t _cs_pin;
+
+  // ensure we can't initialise twice
+  unsigned _initialised:1;
 };
 
 #endif // __AP_INERTIAL_SENSOR_MPU6000_H__