diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
index 87bcdf17a4..d4dc31b1e6 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
@@ -283,7 +283,7 @@ void NavEKF3_core::readIMUData()
     dtIMUavg = ins.get_loop_delta_t();
 
     // the imu sample time is used as a common time reference throughout the filter
-    imuSampleTime_ms = AP_HAL::millis();
+    imuSampleTime_ms = frontend->imuSampleTime_us / 1000;
 
     // use the nominated imu or primary if not available
     if (ins.use_accel(imu_index)) {
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp
index 183e4e38d2..0ee24eec08 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_core.cpp
@@ -498,9 +498,6 @@ void NavEKF3_core::UpdateFilter(bool predict)
 
     // TODO - in-flight restart method
 
-    //get starting time for update step
-    imuSampleTime_ms = frontend->imuSampleTime_us / 1000;
-
     // Check arm status and perform required checks and mode changes
     controlFilterModes();