diff --git a/lisa/tests/scheduler/load_tracking.py b/lisa/tests/scheduler/load_tracking.py
index f5518e4175a7b495c284c211096291d274122dbf..747bd26fe697c70bcd22b335e7585e663e129204 100644
--- a/lisa/tests/scheduler/load_tracking.py
+++ b/lisa/tests/scheduler/load_tracking.py
@@ -216,6 +216,9 @@ class InvarianceItemBase(RTATestBundle, LoadTrackingHelpers, TestBundle, Exekall
         # task will fit even at the lowest OPP
         duty_cycle_pct //= 2
 
+        # Catch rt-app calibration induced issues early.
+        assert duty_cycle_pct > 0
+
         return {
             f"{cls.task_prefix}{cpu}": RTAPhase(
                 prop_wload=PeriodicWload(