diff --git a/os_win/tests/unit/test_base.py b/os_win/tests/unit/test_base.py
index 6e689495..8a58f193 100644
--- a/os_win/tests/unit/test_base.py
+++ b/os_win/tests/unit/test_base.py
@@ -19,6 +19,8 @@ from oslotest import base
 from oslotest import mock_fixture
 from six.moves import builtins
 
+import os
+
 from os_win import exceptions
 from os_win.utils import baseutils
 
@@ -66,6 +68,13 @@ class OsWinBaseTestCase(BaseTestCase):
         mock_os = mock.MagicMock(Version='6.3.0')
         self._mock_wmi.WMI.return_value.Win32_OperatingSystem.return_value = (
             [mock_os])
-        wmi_patcher = mock.patch.object(builtins, 'wmi', create=True,
-                                        new=self._mock_wmi)
+
+        if os.name == 'nt':
+            # The wmi module is expected to exist and by the time this runs,
+            # the tested module will have imported it already.
+            wmi_patcher = mock.patch('wmi.WMI', new=self._mock_wmi.WMI)
+        else:
+            # The wmi module doesn't exist, we'll have to "create" it.
+            wmi_patcher = mock.patch.object(builtins, 'wmi', create=True,
+                                            new=self._mock_wmi)
         wmi_patcher.start()
diff --git a/os_win/tests/unit/test_utilsfactory.py b/os_win/tests/unit/test_utilsfactory.py
index d30aafd8..3698cc9a 100644
--- a/os_win/tests/unit/test_utilsfactory.py
+++ b/os_win/tests/unit/test_utilsfactory.py
@@ -126,7 +126,8 @@ class TestHyperVUtilsFactory(test_base.OsWinBaseTestCase):
             expected_class=diskutils.DiskUtils,
             class_type='diskutils')
 
-    def test_get_clusterutils(self):
+    @mock.patch.object(clusterutils.ClusterUtils, '_init_hyperv_conn')
+    def test_get_clusterutils(self, mock_init_conn):
         self._check_get_class(
             expected_class=clusterutils.ClusterUtils,
             class_type='clusterutils')
diff --git a/os_win/tests/unit/utils/compute/test_clusterutils.py b/os_win/tests/unit/utils/compute/test_clusterutils.py
index fd9641d5..a193a575 100644
--- a/os_win/tests/unit/utils/compute/test_clusterutils.py
+++ b/os_win/tests/unit/utils/compute/test_clusterutils.py
@@ -43,7 +43,8 @@ class ClusterUtilsTestCase(test_base.OsWinBaseTestCase):
     _FAKE_VM_NAME = 'instance-00000001'
     _FAKE_RESOURCEGROUP_NAME = 'Virtual Machine %s' % _FAKE_VM_NAME
 
-    def setUp(self):
+    @mock.patch.object(clusterutils.ClusterUtils, '_init_hyperv_conn')
+    def setUp(self, mock_get_wmi_conn):
         super(ClusterUtilsTestCase, self).setUp()
         self._clusterutils = clusterutils.ClusterUtils()
         self._clusterutils._conn_cluster = mock.MagicMock()
diff --git a/os_win/tests/unit/utils/test_baseutils.py b/os_win/tests/unit/utils/test_baseutils.py
index e967c228..d83f669e 100644
--- a/os_win/tests/unit/utils/test_baseutils.py
+++ b/os_win/tests/unit/utils/test_baseutils.py
@@ -15,6 +15,8 @@
 import mock
 import six
 
+import imp
+
 from os_win.tests.unit import test_base
 from os_win.utils import baseutils
 
@@ -26,6 +28,7 @@ class BaseUtilsTestCase(test_base.OsWinBaseTestCase):
         super(BaseUtilsTestCase, self).setUp()
         self.utils = baseutils.BaseUtils()
         self.utils._conn = mock.MagicMock()
+        mock.patch.object(imp, 'load_source').start()
 
     @mock.patch.object(baseutils, 'wmi', create=True)
     def test_get_wmi_obj(self, mock_wmi):
@@ -80,6 +83,7 @@ class BaseUtilsVirtTestCase(test_base.OsWinBaseTestCase):
         self.utils = baseutils.BaseUtilsVirt()
         self.utils._conn_attr = mock.MagicMock()
         baseutils.BaseUtilsVirt._os_version = None
+        mock.patch.object(imp, 'load_source').start()
 
     @mock.patch.object(baseutils.BaseUtilsVirt, '_get_wmi_conn')
     def test_conn(self, mock_get_wmi_conn):
@@ -97,21 +101,20 @@ class BaseUtilsVirtTestCase(test_base.OsWinBaseTestCase):
         self.assertEqual(expected, self.utils._vs_man_svc)
         self.assertEqual(expected, self.utils._vs_man_svc_attr)
 
-    @mock.patch.object(baseutils, 'imp')
     @mock.patch.object(baseutils, 'wmi', create=True)
-    def test_vs_man_svc_2012(self, mock_wmi, mock_imp):
+    def test_vs_man_svc_2012(self, mock_wmi):
         baseutils.BaseUtilsVirt._old_wmi = None
         mock_os = mock.MagicMock(Version='6.2.0')
         mock_wmi.WMI.return_value.Win32_OperatingSystem.return_value = [
             mock_os]
         fake_module_path = '/fake/path/to/module'
         mock_wmi.__path__ = [fake_module_path]
-        old_conn = mock_imp.load_source.return_value.WMI.return_value
+        old_conn = imp.load_source.return_value.WMI.return_value
 
         expected = old_conn.Msvm_VirtualSystemManagementService()[0]
         self.assertEqual(expected, self.utils._vs_man_svc)
         self.assertIsNone(self.utils._vs_man_svc_attr)
-        mock_imp.load_source.assert_called_once_with(
+        imp.load_source.assert_called_once_with(
             'old_wmi', '%s.py' % fake_module_path)
 
     @mock.patch.object(baseutils.BaseUtilsVirt, '_get_wmi_compat_conn')