diff --git a/neutron/tests/unit/embrane/test_embrane_defaults.py b/neutron/tests/unit/embrane/test_embrane_defaults.py
index 1bb6a565ec6..ea84d63abfd 100644
--- a/neutron/tests/unit/embrane/test_embrane_defaults.py
+++ b/neutron/tests/unit/embrane/test_embrane_defaults.py
@@ -17,17 +17,11 @@
 #
 # @author:  Ivar Lazzaro, Embrane, Inc.
 
-import sys
-
-import mock
 from oslo.config import cfg
 
 from neutron.plugins.embrane.common import config  # noqa
 from neutron.tests import base
 
-# Need to mock heleosapi.
-sys.modules["heleosapi"] = mock.Mock()
-
 
 class ConfigurationTest(base.BaseTestCase):
 
diff --git a/neutron/tests/unit/embrane/test_embrane_l3_plugin.py b/neutron/tests/unit/embrane/test_embrane_l3_plugin.py
index 5bdc9f8808c..548a1d43248 100644
--- a/neutron/tests/unit/embrane/test_embrane_l3_plugin.py
+++ b/neutron/tests/unit/embrane/test_embrane_l3_plugin.py
@@ -17,9 +17,6 @@
 #
 # @author:  Ivar Lazzaro, Embrane, Inc.
 
-import sys
-
-import mock
 from oslo.config import cfg
 
 from neutron.db import api as db
@@ -29,7 +26,6 @@ from neutron.tests.unit import test_l3_plugin as router_test
 
 PLUGIN_NAME = ('neutron.plugins.embrane.plugins.embrane_fake_plugin.'
                'EmbraneFakePlugin')
-sys.modules["heleosapi"] = mock.Mock()
 
 
 class TestEmbraneL3NatDBTestCase(router_test.L3NatDBIntTestCase):
diff --git a/neutron/tests/unit/embrane/test_embrane_neutron_plugin.py b/neutron/tests/unit/embrane/test_embrane_neutron_plugin.py
index bc96b2681db..74b64e41512 100644
--- a/neutron/tests/unit/embrane/test_embrane_neutron_plugin.py
+++ b/neutron/tests/unit/embrane/test_embrane_neutron_plugin.py
@@ -16,7 +16,6 @@
 #    under the License.
 #
 # @author:  Ivar Lazzaro, Embrane, Inc.
-
 import sys
 
 import mock
@@ -28,7 +27,6 @@ from neutron.tests.unit import test_db_plugin as test_plugin
 
 PLUGIN_NAME = ('neutron.plugins.embrane.plugins.embrane_fake_plugin.'
                'EmbraneFakePlugin')
-sys.modules["heleosapi"] = mock.Mock()
 
 
 class EmbranePluginV2TestCase(test_plugin.NeutronDbPluginV2TestCase):
@@ -36,7 +34,11 @@ class EmbranePluginV2TestCase(test_plugin.NeutronDbPluginV2TestCase):
 
     def setUp(self):
         cfg.CONF.set_override('admin_password', "admin123", 'heleos')
+        p = mock.patch.dict(sys.modules, {'heleosapi': mock.Mock()})
+        p.start()
         self.addCleanup(db.clear_db)
+        # dict patches must be explicitly stopped
+        self.addCleanup(p.stop)
         super(EmbranePluginV2TestCase, self).setUp(self._plugin_name)
 
 
diff --git a/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_embrane_defaults.py b/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_embrane_defaults.py
index d3588f8b7e8..cffb2ae3731 100644
--- a/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_embrane_defaults.py
+++ b/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_embrane_defaults.py
@@ -17,16 +17,11 @@
 #
 # @author:  Ivar Lazzaro, Embrane, Inc.
 
-import sys
-
-import mock
 from oslo.config import cfg
 
 from neutron.services.loadbalancer.drivers.embrane import config  # noqa
 from neutron.tests import base
 
-sys.modules["heleosapi"] = mock.Mock()
-
 
 class ConfigurationTest(base.BaseTestCase):
 
diff --git a/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_plugin_driver.py b/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_plugin_driver.py
index c98ef5f1325..56a02a2082d 100644
--- a/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_plugin_driver.py
+++ b/neutron/tests/unit/services/loadbalancer/drivers/embrane/test_plugin_driver.py
@@ -20,16 +20,19 @@
 import sys
 
 import mock
-sys.modules["heleosapi"] = mock.Mock()
 from oslo.config import cfg
 
 from neutron import context
 from neutron.openstack.common.db import exception as n_exc
+from neutron.tests.unit.db.loadbalancer import test_db_loadbalancer
+
+HELEOSAPIMOCK = mock.Mock()
+sys.modules["heleosapi"] = HELEOSAPIMOCK
 from neutron.services.loadbalancer.drivers.embrane import config  # noqa
 from neutron.services.loadbalancer.drivers.embrane import constants as h_con
 from neutron.services.loadbalancer.drivers.embrane import db as h_db
-from neutron.tests.unit.db.loadbalancer import test_db_loadbalancer
-
+# Stop the mock from persisting indefinitely in the global modules space
+del sys.modules["heleosapi"]
 
 EMBRANE_PROVIDER = ('LOADBALANCER:lbaas:neutron.services.'
                     'loadbalancer.drivers.embrane.driver.'
@@ -42,10 +45,12 @@ class TestLoadBalancerPluginBase(
     def setUp(self):
         cfg.CONF.set_override('admin_password', "admin123", 'heleoslb')
         cfg.CONF.set_override('sync_interval', 0, 'heleoslb')
-
+        mock.patch.dict(sys.modules, {'heleosapi': HELEOSAPIMOCK}).start()
         super(TestLoadBalancerPluginBase, self).setUp(
             lbaas_provider=EMBRANE_PROVIDER)
         self.driver = self.plugin.drivers['lbaas']
+        # prevent module mock from saving calls between tests
+        self.addCleanup(HELEOSAPIMOCK.reset_mock)
 
 
 class TestLoadBalancerPlugin(test_db_loadbalancer.TestLoadBalancer,