--- a/etherlab/etherlab.py	Sat Sep 29 16:39:25 2018 +0300
+++ b/etherlab/etherlab.py	Sat Sep 29 16:40:56 2018 +0300
@@ -58,7 +58,7 @@
     ("PDO type", str, "")]
 
 
-class EntryListFactory:
+class EntryListFactory(object):
 
     def __init__(self, entries):
         self.Entries = entries
@@ -154,7 +154,7 @@
     group["children"].sort(GroupItemCompare)
 
 
-class ModulesLibrary:
+class ModulesLibrary(object):
 
     MODULES_EXTRA_PARAMS = [
         (
@@ -409,7 +409,7 @@
     os.path.join(USERDATA_DIR, "ethercat_modules"))
 
 
-class RootClass:
+class RootClass(object):
 
     CTNChildrenTypes = [("EthercatNode", _EthercatCTN, "Ethercat Master")]
     EditorType = LibraryEditor