diff --git a/tryton/gui/window/view_form/view/form_gtk/many2one.py b/tryton/gui/window/view_form/view/form_gtk/many2one.py
index fc5b0d3496..fbeebaa53f 100644
--- a/tryton/gui/window/view_form/view/form_gtk/many2one.py
+++ b/tryton/gui/window/view_form/view/form_gtk/many2one.py
@@ -286,6 +286,7 @@ class Many2One(WidgetInterface):
                 and editable):
             self.sig_activate(widget, event, key_press=True)
         elif (self.has_target(self.field.get(self.record))
+                and editable
                 and event.keyval in (gtk.keysyms.Delete,
                     gtk.keysyms.BackSpace)):
             self.wid_text.set_text('')
diff --git a/tryton/gui/window/win_search.py b/tryton/gui/window/win_search.py
index 7904820a0a..0f901d4cbc 100644
--- a/tryton/gui/window/win_search.py
+++ b/tryton/gui/window/win_search.py
@@ -120,6 +120,8 @@ class WinSearch(NoModal):
                     record = screen.current_record
                     res = [(record.id, record.value.get('rec_name', ''))]
                     self.callback(res)
+                else:
+                    self.callback(None)
             self.destroy()
             WinForm(screen, callback, new=True)
             return