diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index 55e5addb..75008d6f 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -348,6 +348,11 @@ class DictField(BaseField):
     .. versionadded:: 0.3
     """
 
+    def __init__(self, basecls=None, *args, **kwargs):
+        self.basecls = basecls or BaseField
+        assert issubclass(self.basecls, BaseField)
+        super(DictField, self).__init__(*args, **kwargs)
+
     def validate(self, value):
         """Make sure that a list of valid fields is being used.
         """
@@ -360,7 +365,7 @@ class DictField(BaseField):
                                   'contain "." or "$" characters')
 
     def lookup_member(self, member_name):
-        return BaseField(db_field=member_name)
+        return self.basecls(db_field=member_name)
 
 class GeoLocationField(DictField):
     """Supports geobased fields"""
diff --git a/mongoengine/queryset.py b/mongoengine/queryset.py
index 396a745c..11b5321a 100644
--- a/mongoengine/queryset.py
+++ b/mongoengine/queryset.py
@@ -313,7 +313,7 @@ class QuerySet(object):
             op = None
             if parts[-1] in operators + match_operators:
                 op = parts.pop()
-            
+
             if _doc_cls:
                 # Switch field names to proper names [set in Field(name='foo')]
                 fields = QuerySet._lookup_field(_doc_cls, parts)