diff --git a/tryton/gui/window/view_form/view/form_gtk/char.py b/tryton/gui/window/view_form/view/form_gtk/char.py
index 6face14b52..cd74964236 100644
--- a/tryton/gui/window/view_form/view/form_gtk/char.py
+++ b/tryton/gui/window/view_form/view/form_gtk/char.py
@@ -142,11 +142,12 @@ class Char(Widget, TranslateMixin, PopdownMixin):
         sensitivity = {True: gtk.SENSITIVITY_OFF, False: gtk.SENSITIVITY_AUTO}
         super(Char, self)._readonly_set(value)
         if self.autocomplete:
-            self.entry.get_child().set_editable(not value)
+            entry_editable = self.entry.get_child()
             self.entry.set_button_sensitivity(sensitivity[value])
         else:
-            self.entry.set_editable(not value)
-        set_widget_style(self.entry, not value)
+            entry_editable = self.entry
+        entry_editable.set_editable(not value)
+        set_widget_style(entry_editable, not value)
         if value and CONFIG['client.fast_tabbing']:
             self.widget.set_focus_chain([])
         else: