diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index 01d46083b2..3e7b932808 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -590,7 +590,11 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         mi.pubdate     = self.pubdate(idx, index_is_id=index_is_id)
         mi.uuid        = self.uuid(idx, index_is_id=index_is_id)
         mi.title_sort  = self.title_sort(idx, index_is_id=index_is_id)
-        mi.formats     = self.formats(idx, index_is_id=index_is_id).split(',')
+        mi.formats     = self.formats(idx, index_is_id=index_is_id)
+        if hasattr(mi.formats, 'split'):
+            mi.formats = mi.formats.split(',')
+        else:
+            mi.formats = None
         tags = self.tags(idx, index_is_id=index_is_id)
         if tags:
             mi.tags = [i.strip() for i in tags.split(',')]