diff --git a/plone/formwidget/contenttree/source.py b/plone/formwidget/contenttree/source.py
index 8a1cee5..2666a68 100644
--- a/plone/formwidget/contenttree/source.py
+++ b/plone/formwidget/contenttree/source.py
@@ -141,7 +141,7 @@ class PathSource(object):
 
         try:
             results = (self.getTermByBrain(brain, real_value=False)
-                       for brain in self.catalog(**catalog_query))
+                       for brain in self.catalog(**catalog_query) if brain)
         except ParseError:
             return []