diff --git a/releasenotes/notes/deprecate-nova-api-extensions-df16b02485dae203.yaml b/releasenotes/notes/deprecate-nova-api-extensions-df16b02485dae203.yaml
new file mode 100644
index 0000000..c2d9a9b
--- /dev/null
+++ b/releasenotes/notes/deprecate-nova-api-extensions-df16b02485dae203.yaml
@@ -0,0 +1,7 @@
+---
+deprecations:
+  - The *api_extensions* config option in the *compute-feature-enabled* group is
+    now deprecated. This option will be removed from tempest when all the
+    OpenStack releases supported by tempest no longer support the API extensions
+    mechanism. This was removed from Nova during the Newton cycle, so this will
+    be removed at the Mitaka EOL.
diff --git a/tempest/config.py b/tempest/config.py
index f6c89ae..4d8b462 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -318,7 +318,13 @@
                 help='A list of enabled compute extensions with a special '
                      'entry all which indicates every extension is enabled. '
                      'Each extension should be specified with alias name. '
-                     'Empty list indicates all extensions are disabled'),
+                     'Empty list indicates all extensions are disabled',
+                     deprecated_for_removal=True,
+                     deprecated_reason='The Nova extensions API and mechanism '
+                                       'is deprecated. This option will be '
+                                       'removed when all releases supported '
+                                       'by tempest no longer contain the Nova '
+                                       'extensions API and mechanism.'),
     cfg.BoolOpt('change_password',
                 default=False,
                 help="Does the test environment support changing the admin "