diff --git a/ogs6py/_version.py b/ogs6py/_version.py
index 0d59a84..d7d6487 100644
--- a/ogs6py/_version.py
+++ b/ogs6py/_version.py
@@ -1,3 +1,3 @@
 # -*- coding: utf-8 -*-
 """Provide a central version."""
-__version__ = "0.401"
+__version__ = "0.402"
diff --git a/ogs6py/classes/build_tree.py b/ogs6py/classes/build_tree.py
index 5ee160d..d5262ef 100644
--- a/ogs6py/classes/build_tree.py
+++ b/ogs6py/classes/build_tree.py
@@ -30,7 +30,7 @@ def _convertargs(cls, args):
                 args[item] = str(value)
 
     @classmethod
-    def populate_tree(cls, parent, tag, text='', attr=None, overwrite=False):
+    def populate_tree(cls, parent, tag, text=None, attr=None, overwrite=False):
         """
         method to create dictionary from an xml entity
         """