diff --git a/dhlab/text/corpus.py b/dhlab/text/corpus.py
index d24dfd2..fdd9497 100644
--- a/dhlab/text/corpus.py
+++ b/dhlab/text/corpus.py
@@ -30,7 +30,7 @@ class Corpus(DhlabObj):
 
     def __init__(
         self,
-        doctype=None,
+        doctype="digibok",
         author=None,
         freetext=None,
         fulltext=None,