diff --git a/python/obitools3/parsers/universal.pyx b/python/obitools3/parsers/universal.pyx
index beb309c..4366e1d 100755
--- a/python/obitools3/parsers/universal.pyx
+++ b/python/obitools3/parsers/universal.pyx
@@ -133,7 +133,7 @@ def entryIteratorFactory(lineiterator,
                                  only=only,
                                  firstline=first,
                                  buffersize=buffersize),
-                    dict,
+                    Nuc_Seq,
                     format)
     
     raise NotImplementedError('File format iterator not implemented yet')