diff --git a/nova/tests/unit/virt/hyperv/__init__.py b/nova/tests/unit/virt/hyperv/__init__.py
index e69de29bb2d1..2190f0570ff8 100644
--- a/nova/tests/unit/virt/hyperv/__init__.py
+++ b/nova/tests/unit/virt/hyperv/__init__.py
@@ -0,0 +1,20 @@
+# 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 unittest
+
+try:
+    import os_win  # noqa: F401
+except ImportError:
+    raise unittest.SkipTest(
+        "The 'os-win' dependency is not installed."
+    )
diff --git a/nova/tests/unit/virt/powervm/__init__.py b/nova/tests/unit/virt/powervm/__init__.py
index dedb6af7db10..3f8ef7b16717 100644
--- a/nova/tests/unit/virt/powervm/__init__.py
+++ b/nova/tests/unit/virt/powervm/__init__.py
@@ -11,13 +11,22 @@
 #    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 unittest
+
 from oslo_utils.fixture import uuidsentinel
 
 from nova.compute import power_state
 from nova.compute import vm_states
 from nova import objects
 
+try:
+    import powervm  # noqa: F401
+except ImportError:
+    raise unittest.SkipTest(
+        "The 'pypowervm' dependency is not installed."
+    )
+
 
 TEST_FLAVOR = objects.flavor.Flavor(
     memory_mb=2048,
diff --git a/nova/tests/unit/virt/vmwareapi/__init__.py b/nova/tests/unit/virt/vmwareapi/__init__.py
index e69de29bb2d1..206b60cb8fed 100644
--- a/nova/tests/unit/virt/vmwareapi/__init__.py
+++ b/nova/tests/unit/virt/vmwareapi/__init__.py
@@ -0,0 +1,20 @@
+# 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 unittest
+
+try:
+    import oslo_vmware  # noqa: F401
+except ImportError:
+    raise unittest.SkipTest(
+        "The 'oslo.vmware' dependency is not installed."
+    )
diff --git a/nova/tests/unit/virt/zvm/__init__.py b/nova/tests/unit/virt/zvm/__init__.py
index e69de29bb2d1..a93e19e1be56 100644
--- a/nova/tests/unit/virt/zvm/__init__.py
+++ b/nova/tests/unit/virt/zvm/__init__.py
@@ -0,0 +1,20 @@
+# 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 unittest
+
+try:
+    import zvmconnector  # noqa: F401
+except ImportError:
+    raise unittest.SkipTest(
+        "The 'zVMCloudConnector' dependency is not installed."
+    )
diff --git a/requirements.txt b/requirements.txt
index 46a611b1debb..c053e1e2202e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,8 +8,6 @@ lxml>=4.5.0 # BSD
 Routes>=2.3.1 # MIT
 cryptography>=2.7 # BSD/Apache-2.0
 WebOb>=1.8.2 # MIT
-# NOTE(mriedem): greenlet 0.4.14 does not work with older versions of gcc on
-# ppc64le systems, see https://github.com/python-greenlet/greenlet/issues/136.
 greenlet>=0.4.15 # MIT
 PasteDeploy>=1.5.0 # MIT
 Paste>=2.0.2 # MIT
@@ -52,17 +50,14 @@ os-brick>=4.3.1 # Apache-2.0
 os-resource-classes>=1.1.0 # Apache-2.0
 os-traits>=2.5.0 # Apache-2.0
 os-vif>=1.15.2 # Apache-2.0
-os-win>=5.4.0 # Apache-2.0
 castellan>=0.16.0 # Apache-2.0
 microversion-parse>=0.2.1 # Apache-2.0
 tooz>=1.58.0 # Apache-2.0
 cursive>=0.2.1 # Apache-2.0
-pypowervm>=1.1.15 # Apache-2.0
 retrying>=1.3.3,!=1.3.0 # Apache-2.0
 os-service-types>=1.7.0 # Apache-2.0
 taskflow>=3.8.0 # Apache-2.0
 python-dateutil>=2.7.0 # BSD
-zVMCloudConnector>=1.3.0;sys_platform!='win32'  # Apache 2.0 License
 futurist>=1.8.0 # Apache-2.0
 openstacksdk>=0.35.0 # Apache-2.0
 dataclasses>=0.7;python_version=='3.6'  # Apache 2.0 License
diff --git a/setup.cfg b/setup.cfg
index 3857fd5e473d..99d7cdaf104d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -30,6 +30,14 @@ classifiers =
 [extras]
 osprofiler =
     osprofiler>=1.4.0 # Apache-2.0
+powervm =
+    pypowervm>=1.1.15 # Apache-2.0
+zvm =
+    zVMCloudConnector>=1.3.0;sys_platform!='win32'  # Apache 2.0 License
+hyperv =
+    os-win>=5.4.0 # Apache-2.0
+vmware =
+    oslo.vmware>=3.6.0 # Apache-2.0
 
 [files]
 data_files =
diff --git a/test-requirements.txt b/test-requirements.txt
index 3f3c1c0cb5e6..3194e9dd6637 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -23,6 +23,3 @@ testtools>=2.5.0 # MIT
 bandit>=1.1.0 # Apache-2.0
 gabbi>=1.35.0 # Apache-2.0
 wsgi-intercept>=1.7.0 # MIT License
-
-# vmwareapi driver specific dependencies
-oslo.vmware>=3.6.0 # Apache-2.0