diff --git a/ostap/io/sqliteshelve.py b/ostap/io/sqliteshelve.py
index 4eb40933..3cddd829 100755
--- a/ostap/io/sqliteshelve.py
+++ b/ostap/io/sqliteshelve.py
@@ -145,7 +145,7 @@
 # =============================================================================
 ##  ordered dict type to be used 
 ordered_dict = dict
-if python_info < (3.7) :
+if python_info < (3,7) :
     from collections import OrderedDict as ordered_dict 
 # =============================================================================
 _modes_ = {