diff --git a/.travis.yml b/.travis.yml
index f9348e7..659395e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -80,8 +80,7 @@ install:
   - export PATH=${HOME}/maintainer-quality-tools/travis:${PATH}
   - travis_install_nightly
   - pip install -e .
-  - mv tests/test_helper test_helper
-  - mv tests/test_helper_bis test_helper_bis
+  - mv tests/test_helper* .
 
 script:
   - travis_run_tests
diff --git a/tests/test_helper_extended/__init__.py b/tests/test_helper_extended/__init__.py
new file mode 100644
index 0000000..0650744
--- /dev/null
+++ b/tests/test_helper_extended/__init__.py
@@ -0,0 +1 @@
+from . import models
diff --git a/tests/test_helper_extended/__manifest__.py b/tests/test_helper_extended/__manifest__.py
new file mode 100644
index 0000000..1043ce3
--- /dev/null
+++ b/tests/test_helper_extended/__manifest__.py
@@ -0,0 +1,19 @@
+# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
+
+
+{
+    "name": "Test Helper Extended",
+    "summary": "Another fake module extending fake module Test Helper for testing",
+    "version": "0.0.0",
+    "category": "Uncategorized",
+    "website": "www.akretion.com",
+    "author": " Akretion",
+    "license": "LGPL-3",
+    "application": False,
+    "installable": True,
+    "external_dependencies": {"python": [], "bin": []},
+    "depends": ["test_helper"],
+    "data": [],
+    "demo": [],
+    "qweb": [],
+}
diff --git a/tests/test_helper_extended/models/__init__.py b/tests/test_helper_extended/models/__init__.py
new file mode 100644
index 0000000..34dd130
--- /dev/null
+++ b/tests/test_helper_extended/models/__init__.py
@@ -0,0 +1 @@
+from . import test_mixin
diff --git a/tests/test_helper_extended/models/test_mixin.py b/tests/test_helper_extended/models/test_mixin.py
new file mode 100644
index 0000000..b9bc1dd
--- /dev/null
+++ b/tests/test_helper_extended/models/test_mixin.py
@@ -0,0 +1,10 @@
+# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
+
+from odoo import fields, models
+
+
+class TestMixin(models.AbstractModel):
+    _inherit = "test.mixin"
+    _description = "Test Mixin Extension"
+
+    test_char_02 = fields.Char()
diff --git a/tests/test_helper_extended/tests/__init__.py b/tests/test_helper_extended/tests/__init__.py
new file mode 100644
index 0000000..ff72a1f
--- /dev/null
+++ b/tests/test_helper_extended/tests/__init__.py
@@ -0,0 +1 @@
+from . import test_registry
diff --git a/tests/test_helper_extended/tests/test_registry.py b/tests/test_helper_extended/tests/test_registry.py
new file mode 100644
index 0000000..4b831e3
--- /dev/null
+++ b/tests/test_helper_extended/tests/test_registry.py
@@ -0,0 +1,33 @@
+# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
+
+from odoo.release import version_info
+
+if version_info[0] >= 15:
+    from odoo.tests import TransactionCase
+
+    from odoo_test_helper import FakeModelLoader
+
+    class TestMixin(TransactionCase):
+        def test_mixin_after_reloading_parent_module(self):
+            self.assertIn("test.mixin", self.env.registry)
+            self.assertIn("test_char", self.env["test.mixin"]._fields)
+            self.assertIn("test_char_02", self.env["test.mixin"]._fields)
+
+            loader = FakeModelLoader(self.env, "odoo.addons.test_helper")
+            loader.backup_registry()
+
+            # trigger reload of parent module: test_helper
+            loader.update_registry(())
+
+            self.assertIn("test.mixin", self.env.registry)
+            self.assertIn("test_char", self.env["test.mixin"]._fields)
+            # new field should not be there anymore
+            self.assertNotIn("test_char_02", self.env["test.mixin"]._fields)
+
+            # but now we restore registry
+            loader.restore_registry()
+
+            self.assertIn("test.mixin", self.env.registry)
+            self.assertIn("test_char", self.env["test.mixin"]._fields)
+            # new field should be there again
+            self.assertIn("test_char_02", self.env["test.mixin"]._fields)