diff --git a/platforms/posix/src/px4_layer/drv_hrt.cpp b/platforms/posix/src/px4_layer/drv_hrt.cpp
index 06b3e5d764..874ce5db3a 100644
--- a/platforms/posix/src/px4_layer/drv_hrt.cpp
+++ b/platforms/posix/src/px4_layer/drv_hrt.cpp
@@ -205,7 +205,7 @@ hrt_abstime ts_to_abstime(const struct timespec *ts)
  * This function is safe to use even if the timestamp is updated
  * by an interrupt during execution.
  */
-hrt_abstime hrt_elapsed_time(const volatile hrt_abstime *then)
+hrt_abstime hrt_elapsed_time(const hrt_abstime *then)
 {
 	hrt_abstime delta = hrt_absolute_time() - *then;
 	return delta;
diff --git a/src/modules/px4iofirmware/controls.c b/src/modules/px4iofirmware/controls.c
index 650a84db03..25129b778a 100644
--- a/src/modules/px4iofirmware/controls.c
+++ b/src/modules/px4iofirmware/controls.c
@@ -460,7 +460,7 @@ controls_tick()
 	 * If we haven't seen any new control data in 200ms, assume we
 	 * have lost input.
 	 */
-	if (!rc_input_lost && hrt_elapsed_time(&system_state.rc_channels_timestamp_received) > 200000) {
+	if (!rc_input_lost && hrt_elapsed_time_atomic(&system_state.rc_channels_timestamp_received) > 200000) {
 		rc_input_lost = true;
 
 		/* clear the input-kind flags here */
diff --git a/src/modules/px4iofirmware/mixer.cpp b/src/modules/px4iofirmware/mixer.cpp
index c873c6f220..b6fbf261c0 100644
--- a/src/modules/px4iofirmware/mixer.cpp
+++ b/src/modules/px4iofirmware/mixer.cpp
@@ -119,7 +119,7 @@ mixer_tick(void)
 
 	/* check that we are receiving fresh data from the FMU */
 	if ((system_state.fmu_data_received_time == 0) ||
-	    hrt_elapsed_time(&system_state.fmu_data_received_time) > FMU_INPUT_DROP_LIMIT_US) {
+	    hrt_elapsed_time_atomic(&system_state.fmu_data_received_time) > FMU_INPUT_DROP_LIMIT_US) {
 
 		/* too long without FMU input, time to go to failsafe */
 		if (r_status_flags & PX4IO_P_STATUS_FLAGS_FMU_OK) {