diff -r 70a76083c59c -r 8f3cb4b47cbb xmlclass/xmlclass.py
--- a/xmlclass/xmlclass.py	Thu Jul 22 12:03:34 2021 +0200
+++ b/xmlclass/xmlclass.py	Fri Jul 23 13:15:19 2021 +0200
@@ -1522,7 +1522,7 @@
                     raise ValueError("Wrong path!")
                 if attributes[parts[0]]["attr_type"]["basename"] == "boolean":
                     setattr(self, parts[0], value)
-                elif attributes[parts[0]]["use"] == "optional" and value == "":
+                elif attributes[parts[0]]["use"] == "optional" and value == None:
                     if "default" in attributes[parts[0]]:
                         setattr(self, parts[0],
                                 attributes[parts[0]]["attr_type"]["extract"](