diff --git a/fieldservice/models/fsm_order.py b/fieldservice/models/fsm_order.py
index 9465a3a146..c311e858a2 100644
--- a/fieldservice/models/fsm_order.py
+++ b/fieldservice/models/fsm_order.py
@@ -312,7 +312,7 @@ def _calc_scheduled_dates(self, vals):
                 vals["scheduled_date_start"] = str(date_to_with_delta)
 
             elif (
-                vals.get("scheduled_duration", False) is not None
+                vals.get("scheduled_duration", False)
                 and vals.get("scheduled_date_start", self.scheduled_date_start)
                 and (
                     self.scheduled_date_start != vals.get("scheduled_date_start", False)