diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
index d50691c402..bbb5e8d8ee 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
@@ -63,7 +63,7 @@ bool AP_InertialSensor_HIL::wait_for_sample(uint16_t timeout_ms)
     if (_sample_available()) {
         return true;
     }
-    uint32_t start = hal.scheduler->micros();
+    uint32_t start = hal.scheduler->millis();
     while ((hal.scheduler->millis() - start) < timeout_ms) {
         uint32_t tnow = hal.scheduler->micros();
         uint32_t tdelay = (_last_sample_usec + _sample_period_usec) - tnow;