diff --git a/testing/drivertest/drivertest_timer.c b/testing/drivertest/drivertest_timer.c
index 7e25e9bd2..8694d7156 100644
--- a/testing/drivertest/drivertest_timer.c
+++ b/testing/drivertest/drivertest_timer.c
@@ -258,7 +258,7 @@ static void test_case_timer(FAR void **state)
       tim = get_timestamp();
       usleep(2 * timer_state->interval);
       tim = get_timestamp() - tim;
-      range = timer_state->interval / 1000 - tim;
+      range = abs(timer_state->interval / 1000 - tim);
       assert_in_range(range, 0, timer_state->range);
     }