diff --git a/CHANGELOG b/CHANGELOG
index 57806ee07f..a8209bab89 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Prevent Wizard State name to start with '_'
 * Add completion attribute for Many2One, Many2Many and One2Many
 * Add ViewSearch
 * Add domains on Action Window
diff --git a/trytond/wizard/wizard.py b/trytond/wizard/wizard.py
index 9ee5c91711..78c767457a 100644
--- a/trytond/wizard/wizard.py
+++ b/trytond/wizard/wizard.py
@@ -166,6 +166,8 @@ class Wizard(WarningErrorMixin, URLMixin):
         # Set states
         cls.states = {}
         for attr in dir(cls):
+            if attr.startswith('_'):
+                continue
             if isinstance(getattr(cls, attr), State):
                 cls.states[attr] = getattr(cls, attr)