diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index abb17366a9..85874f3f31 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -1115,6 +1115,8 @@ AP_InertialSensor::_init_gyro()
     // cold start
     hal.console->printf("Init Gyro");
 
+    hal.scheduler->expect_delay_ms(60000);
+
     /*
       we do the gyro calibration with no board rotation. This avoids
       having to rotate readings during the calibration
@@ -1229,6 +1231,8 @@ AP_InertialSensor::_init_gyro()
 
     // stop flashing leds
     AP_Notify::flags.initialising = false;
+
+    hal.scheduler->expect_delay_ms(0);
 }
 
 // save parameters to eeprom
@@ -1693,11 +1697,13 @@ void AP_InertialSensor::acal_update()
         return;
     }
 
+    hal.scheduler->expect_delay_ms(20000);
     _acal->update();
 
     if (hal.util->get_soft_armed() && _acal->get_status() != ACCEL_CAL_NOT_STARTED) {
         _acal->cancel();
     }
+    hal.scheduler->expect_delay_ms(0);
 }
 
 /*