--- a/plcopen/plcopen.py	Fri Sep 22 20:12:22 2017 +0300
+++ b/plcopen/plcopen.py	Thu Sep 28 12:20:40 2017 +0300
@@ -84,7 +84,7 @@
     return v1
 
 
-class rect:
+class rect(object):
     """
     Helper class for bounding_box calculation
     """