diff --git a/modules/account/account.py b/modules/account/account.py
index b36d3cb01c..bd35dfd102 100644
--- a/modules/account/account.py
+++ b/modules/account/account.py
@@ -2329,7 +2329,8 @@ class GeneralLedgerLine(DescriptionOriginMixin, ModelSQL, ModelView):
 
     move = fields.Many2One('account.move', 'Move')
     date = fields.Date('Date')
-    account = fields.Many2One('account.general_ledger.account', 'Account')
+    account = fields.Many2One(
+        'account.general_ledger.account', 'Account', required=True)
     party = fields.Many2One('party.party', 'Party',
         states={
             'invisible': ~Eval('party_required', False),
diff --git a/modules/account_move_line_grouping/account.py b/modules/account_move_line_grouping/account.py
index c74ac09b43..51523f476d 100644
--- a/modules/account_move_line_grouping/account.py
+++ b/modules/account_move_line_grouping/account.py
@@ -40,7 +40,8 @@ class MoveLine(metaclass=PoolMeta):
 class MoveLineGroup(MoveLineMixin, ModelSQL, ModelView):
     __name__ = 'account.move.line.group'
 
-    move = fields.Many2One('account.move', "Move", readonly=True)
+    move = fields.Many2One(
+        'account.move', "Move", readonly=True, required=True)
     account = fields.Many2One(
         'account.account', "Account", readonly=True,
         context={
diff --git a/modules/account_statement/statement.py b/modules/account_statement/statement.py
index 07c7bb708f..99566d4615 100644
--- a/modules/account_statement/statement.py
+++ b/modules/account_statement/statement.py
@@ -1086,7 +1086,8 @@ del _states
 class LineGroup(ModelSQL, ModelView):
     __name__ = 'account.statement.line.group'
     _rec_name = 'number'
-    statement = fields.Many2One('account.statement', 'Statement')
+    statement = fields.Many2One(
+        'account.statement', 'Statement', required=True)
     journal = fields.Function(fields.Many2One('account.statement.journal',
             'Journal'), 'get_journal', searcher='search_journal')
     number = fields.Char('Number')
diff --git a/modules/currency/currency.py b/modules/currency/currency.py
index d4f17bc9c9..1be0ef371d 100644
--- a/modules/currency/currency.py
+++ b/modules/currency/currency.py
@@ -254,7 +254,7 @@ class CurrencyRate(ModelSQL, ModelView):
             ],
         help="The floating exchange rate used to convert the currency.")
     currency = fields.Many2One('currency.currency', 'Currency',
-            ondelete='CASCADE',
+        required=True, ondelete='CASCADE',
         help="The currency on which the rate applies.")
 
     @classmethod
diff --git a/modules/party/party.py b/modules/party/party.py
index 0b40ffdeff..9af034753c 100644
--- a/modules/party/party.py
+++ b/modules/party/party.py
@@ -819,7 +819,7 @@ class Identifier(sequence_ordered(), DeactivableMixin, ModelSQL, ModelView):
     @classmethod
     def __setup__(cls):
         super().__setup__()
-        cls.__access__.update(['party', 'address'])
+        cls.__access__.add('party')
 
     @classmethod
     def __register__(cls, module_name):
diff --git a/modules/product_image/product.py b/modules/product_image/product.py
index 4cf419b49b..01dee6980c 100644
--- a/modules/product_image/product.py
+++ b/modules/product_image/product.py
@@ -237,7 +237,7 @@ class Image(ImageMixin, sequence_ordered(), ModelSQL, ModelView, MatchMixin):
     @classmethod
     def __setup__(cls):
         super().__setup__()
-        cls.__access__.update(['product', 'template'])
+        cls.__access__.add('template')
 
     def _store_cache(self, size, image):
         cache = super()._store_cache(size, image)
diff --git a/modules/product_kit/product.py b/modules/product_kit/product.py
index 27dccf8544..4274fbb0f7 100644
--- a/modules/product_kit/product.py
+++ b/modules/product_kit/product.py
@@ -245,7 +245,7 @@ class Component(ComponentMixin, ModelSQL, ModelView):
     @classmethod
     def __setup__(cls):
         super().__setup__()
-        cls.__access__.update(['parent_template', 'parent_product'])
+        cls.__access__.add('parent_template')
 
     @fields.depends(
         'parent_product', '_parent_parent_product.template')
diff --git a/trytond/trytond/ir/action.py b/trytond/trytond/ir/action.py
index 2f9223296d..e577742f31 100644
--- a/trytond/trytond/ir/action.py
+++ b/trytond/trytond/ir/action.py
@@ -186,7 +186,7 @@ class ActionKeyword(ModelSQL, ModelView):
             ('graph_open', 'Open Graph'),
             ], string='Keyword', required=True)
     model = fields.Reference('Model', selection='models_get')
-    action = fields.Many2One('ir.action', 'Action',
+    action = fields.Many2One('ir.action', 'Action', required=True,
         ondelete='CASCADE')
     groups = fields.Function(
         fields.Many2Many('res.group', None, None, "Groups"),
@@ -973,7 +973,7 @@ class ActionActWindowView(
             ('model', '=', Eval('model', None)),
             ])
     act_window = fields.Many2One('ir.action.act_window', 'Action',
-            ondelete='CASCADE')
+        required=True, ondelete='CASCADE')
     model = fields.Function(fields.Char("Model"), 'on_change_with_model')
 
     @classmethod
diff --git a/trytond/trytond/tests/test_tryton.py b/trytond/trytond/tests/test_tryton.py
index 63ba0d0fa0..d0d5008e7a 100644
--- a/trytond/trytond/tests/test_tryton.py
+++ b/trytond/trytond/tests/test_tryton.py
@@ -416,6 +416,9 @@ class ModuleTestCase(_DBTestCase):
                         msg="Wrong __access__ '%s' for %s" % (
                             field_name, mname))
                     field = Model._fields[field_name]
+                    self.assertTrue(field.required,
+                        msg=("Field '%s' of '%s' must be required in order to "
+                            "be used in __access__") % (field_name, mname))
                     Target = field.get_target()
                     self.assertTrue(
                         Target,