diff --git a/tryton/gui/window/view_form/model/record.py b/tryton/gui/window/view_form/model/record.py
index e90dc96811..364f373929 100644
--- a/tryton/gui/window/view_form/model/record.py
+++ b/tryton/gui/window/view_form/model/record.py
@@ -516,7 +516,7 @@ class Record(SignalEvent):
             scope = values
             for i in arg.split('.'):
                 if i not in scope:
-                    scope = False
+                    scope = None
                     break
                 scope = scope[i]
             res[arg] = scope