diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index e7c3d2df2f..fccb056792 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -368,6 +368,8 @@ AP_InertialSensor::AP_InertialSensor() :
     }
     memset(_delta_velocity_valid,0,sizeof(_delta_velocity_valid));
     memset(_delta_angle_valid,0,sizeof(_delta_angle_valid));
+
+    AP_AccelCal::register_client(this);
 }
 
 /*
@@ -1279,8 +1281,6 @@ void AP_InertialSensor::acal_init()
     if (_accel_calibrator == NULL) {
         _accel_calibrator = new AccelCalibrator[INS_MAX_INSTANCES];
     }
-
-    _acal->register_client(this);
 }
 
 // update accel calibrator