diff --git a/src/collective/z3cform/rolefield/field.py b/src/collective/z3cform/rolefield/field.py
index 0b97686..189dd85 100644
--- a/src/collective/z3cform/rolefield/field.py
+++ b/src/collective/z3cform/rolefield/field.py
@@ -117,7 +117,8 @@ class LocalRolesToPrincipalsDataManager(AttributeField):
         # finally set the value
         super(LocalRolesToPrincipalsDataManager, self).set(value)
 
-        self.context.reindexObjectSecurity()
+        if self.context.id:
+            self.context.reindexObjectSecurity()
 
 import plone.supermodel.exportimport