diff --git a/src/collective/dms/basecontent/widget.py b/src/collective/dms/basecontent/widget.py
index b771d97..1af492f 100644
--- a/src/collective/dms/basecontent/widget.py
+++ b/src/collective/dms/basecontent/widget.py
@@ -9,4 +9,5 @@ def AjaxChosenMultiFieldWidget(field, request):
     widget = z3c.form.widget.FieldWidget(field,
         AjaxChosenMultiSelectionWidget(request))
     widget.populate_select = True
+    widget.ignoreMissing = True
     return widget