diff --git a/composer/schema/field.py b/composer/schema/field.py
index b49e716..1f2ecab 100644
--- a/composer/schema/field.py
+++ b/composer/schema/field.py
@@ -30,7 +30,7 @@ from zope.component import adapts
 from zope import component
 from zope.i18n.format import DateTimeParseError
 from zope.i18n.locales import locales
-from zope.schema.interfaces import IVocabularyFactory
+from zope.schema.interfaces import IVocabularyFactory, IContextSourceBinder
 from zope.tales.engine import Engine
 from zope.tales.tales import Context
 
@@ -137,8 +137,15 @@ class Field(Component):
                 return terms
             voc = voc.splitlines()
             return [dict(token=t, title=t) for t in voc if t.strip()]
-        else:
-            return [dict(token=t.token, title=t.title or t.value) for t in voc]
+        elif IContextSourceBinder.providedBy(voc):
+            source = voc(context)
+            terms = component.queryMultiAdapter((source, request), ITerms)
+            if terms is not None:
+                termsList = [terms.getTerm(value) for value in source]
+                return [dict(token=t.token, title=t.title) for t in termsList]
+            else:
+                return None
+        return [dict(token=t.token, title=t.title or t.value) for t in voc]
 
     def getVocabularyTerms(self, name, context, request):
         if context is None or request is None:
diff --git a/composer/schema/grid/field.py b/composer/schema/grid/field.py
index e5c8152..b2eefc9 100644
--- a/composer/schema/grid/field.py
+++ b/composer/schema/grid/field.py
@@ -162,6 +162,8 @@ class KeyTableFieldInstance(RecordsFieldInstance):
     def display(self, value):
         headers = [fi.context.title for fi in self.columnFieldInstances]
         rows = []
+        if value is None:
+            value = {}
         for k, v in value.items():
             row = [k]
             for idx, fi in enumerate(self.columnFieldInstances[1:]):