diff --git a/tailbone/views/shifts/schedule.py b/tailbone/views/shifts/schedule.py
index 08db8150..26bb65cd 100644
--- a/tailbone/views/shifts/schedule.py
+++ b/tailbone/views/shifts/schedule.py
@@ -83,11 +83,11 @@ class ScheduleView(TimeSheetView):
             # apply delete operations
             deleted = []
             for uuid, value in data['delete'].iteritems():
-                assert value == 'delete'
-                shift = Session.query(model.ScheduledShift).get(uuid)
-                assert shift
-                Session.delete(shift)
-                deleted.append(uuid)
+                if value == 'delete':
+                    shift = self.Session.query(model.ScheduledShift).get(uuid)
+                    if shift:
+                        self.Session.delete(shift)
+                        deleted.append(uuid)
 
             # apply create / update operations
             created = {}