diff --git a/neutron/tests/tools.py b/neutron/tests/tools.py
index 980024c1bce..ffdfffe335c 100644
--- a/neutron/tests/tools.py
+++ b/neutron/tests/tools.py
@@ -13,10 +13,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import importlib
 import os
 import platform
 import random
 import string
+import sys
 import time
 import warnings
 
@@ -24,6 +26,7 @@ import fixtures
 import mock
 import six
 
+import neutron
 from neutron.api.v2 import attributes
 
 
@@ -185,6 +188,36 @@ class UnorderedList(list):
         return not self == other
 
 
+def import_modules_recursively(topdir):
+    '''Import and return all modules below the topdir directory.'''
+    modules = []
+    for root, dirs, files in os.walk(topdir):
+        for file_ in files:
+            if file_[-3:] != '.py':
+                continue
+
+            module = file_[:-3]
+            if module == '__init__':
+                continue
+
+            import_base = root.replace('/', '.')
+
+            # NOTE(ihrachys): in Python3, or when we are not located in the
+            # directory containing neutron code, __file__ is absolute, so we
+            # should truncate it to exclude PYTHONPATH prefix
+            prefixlen = len(os.path.dirname(neutron.__file__))
+            import_base = 'neutron' + import_base[prefixlen:]
+
+            module = '.'.join([import_base, module])
+            if module not in sys.modules:
+                importlib.import_module(module)
+            modules.append(module)
+
+        for dir_ in dirs:
+            modules.extend(import_modules_recursively(dir_))
+    return modules
+
+
 def get_random_string(n=10):
     return ''.join(random.choice(string.ascii_lowercase) for _ in range(n))
 
diff --git a/neutron/tests/unit/objects/test_objects.py b/neutron/tests/unit/objects/test_objects.py
index 341fc0fa26f..08257cf8f55 100644
--- a/neutron/tests/unit/objects/test_objects.py
+++ b/neutron/tests/unit/objects/test_objects.py
@@ -18,7 +18,9 @@ import pprint
 from oslo_versionedobjects import base as obj_base
 from oslo_versionedobjects import fixture
 
+from neutron import objects
 from neutron.tests import base as test_base
+from neutron.tests import tools
 
 
 # NOTE: The hashes in this list should only be changed if they come with a
@@ -32,6 +34,12 @@ object_data = {
 
 class TestObjectVersions(test_base.BaseTestCase):
 
+    def setUp(self):
+        super(TestObjectVersions, self).setUp()
+        # NOTE(ihrachys): seed registry with all objects under neutron.objects
+        # before validating the hashes
+        tools.import_modules_recursively(os.path.dirname(objects.__file__))
+
     def test_versions(self):
         checker = fixture.ObjectVersionChecker(
             obj_base.VersionedObjectRegistry.obj_classes())
diff --git a/neutron/tests/unit/tests/example/README b/neutron/tests/unit/tests/example/README
new file mode 100644
index 00000000000..4eebbde9962
--- /dev/null
+++ b/neutron/tests/unit/tests/example/README
@@ -0,0 +1,2 @@
+This directory is used by:
+neutron.tests.unit.tests.test_tools.ImportModulesRecursivelyTestCase
diff --git a/neutron/tests/unit/tests/example/__init__.py b/neutron/tests/unit/tests/example/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/neutron/tests/unit/tests/example/dir/__init__.py b/neutron/tests/unit/tests/example/dir/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/neutron/tests/unit/tests/example/dir/example_module.py b/neutron/tests/unit/tests/example/dir/example_module.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/neutron/tests/unit/tests/test_tools.py b/neutron/tests/unit/tests/test_tools.py
new file mode 100644
index 00000000000..1ab3e939fda
--- /dev/null
+++ b/neutron/tests/unit/tests/test_tools.py
@@ -0,0 +1,33 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import os
+import sys
+
+from neutron.tests import base
+from neutron.tests import tools
+from neutron.tests.unit import tests  # noqa
+
+
+EXAMPLE_MODULE = 'neutron.tests.unit.tests.example.dir.example_module'
+
+
+class ImportModulesRecursivelyTestCase(base.BaseTestCase):
+
+    def test_object_modules(self):
+        sys.modules.pop(EXAMPLE_MODULE, None)
+        modules = tools.import_modules_recursively(
+            os.path.dirname(tests.__file__))
+        self.assertIn(
+            'neutron.tests.unit.tests.example.dir.example_module',
+            modules)
+        self.assertIn(EXAMPLE_MODULE, sys.modules)