diff --git a/web_access_rule_buttons/models/models.py b/web_access_rule_buttons/models/models.py
index 629778e7..f093feb8 100644
--- a/web_access_rule_buttons/models/models.py
+++ b/web_access_rule_buttons/models/models.py
@@ -18,7 +18,7 @@ class Base(models.AbstractModel):
        :param operation: a list of ``read``, ``create``, ``write``, ``unlink``
        :return: {operation: access} (access is a boolean)
         """
-        if operations or None:
+        if not operations:
             operations = ['read', 'create', 'write', 'unlink']
         result = {}
         for operation in operations:
diff --git a/web_access_rule_buttons/tests/__init__.py b/web_access_rule_buttons/tests/__init__.py
new file mode 100644
index 00000000..1c1376d5
--- /dev/null
+++ b/web_access_rule_buttons/tests/__init__.py
@@ -0,0 +1,3 @@
+# License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl.html).
+
+from . import test_access_rule_buttons
diff --git a/web_access_rule_buttons/tests/test_access_rule_buttons.py b/web_access_rule_buttons/tests/test_access_rule_buttons.py
new file mode 100644
index 00000000..47774b4d
--- /dev/null
+++ b/web_access_rule_buttons/tests/test_access_rule_buttons.py
@@ -0,0 +1,19 @@
+# Copyright 2019 Onestein BV
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+from odoo.tests.common import TransactionCase
+
+
+class TestAccessRuleButtons(TransactionCase):
+    def setUp(self):
+        super(TestAccessRuleButtons, self).setUp()
+
+        self.curr_obj = self.env['res.currency']
+        self.curr_record = self.env.ref('base.USD')
+
+    def test_check_access_rule_1(self):
+        res = self.curr_obj.check_access_rule_all(['write'])
+        self.assertTrue(res['write'])
+
+    def test_check_access_rule_2(self):
+        res = self.curr_record.check_access_rule_all(['write'])
+        self.assertTrue(res['write'])