diff --git a/nova/api/openstack/compute/servers.py b/nova/api/openstack/compute/servers.py
index a5fc979ca3..91c2a221d4 100644
--- a/nova/api/openstack/compute/servers.py
+++ b/nova/api/openstack/compute/servers.py
@@ -323,6 +323,11 @@ class ServersController(wsgi.Controller):
                 context.can(server_policies.SERVERS % 'index:get_all_tenants')
             elevated = context.elevated()
         else:
+            # As explained in lp:#1185290, if `all_tenants` is not passed
+            # we must ignore the `tenant_id` search option. As explained
+            # in a above code comment, any change to this behavior would
+            # require a microversion bump.
+            search_opts.pop('tenant_id', None)
             if context.project_id:
                 search_opts['project_id'] = context.project_id
             else:
diff --git a/nova/tests/unit/api/openstack/compute/test_serversV21.py b/nova/tests/unit/api/openstack/compute/test_serversV21.py
index 60f5001a79..65e4749f78 100644
--- a/nova/tests/unit/api/openstack/compute/test_serversV21.py
+++ b/nova/tests/unit/api/openstack/compute/test_serversV21.py
@@ -779,6 +779,7 @@ class ServersControllerTest(ControllerTest):
     def test_tenant_id_filter_no_admin_context(self):
         def fake_get_all(context, search_opts=None, **kwargs):
             self.assertIsNotNone(search_opts)
+            self.assertNotIn('tenant_id', search_opts)
             self.assertEqual(search_opts['project_id'], 'fake')
             return [fakes.stub_instance_obj(100)]
 
@@ -788,6 +789,21 @@ class ServersControllerTest(ControllerTest):
             servers = self.controller.index(req)['servers']
         self.assertEqual(len(servers), 1)
 
+    def test_tenant_id_filter_admin_context(self):
+        """"Test tenant_id search opt is dropped if all_tenants is not set."""
+        def fake_get_all(context, search_opts=None, **kwargs):
+            self.assertIsNotNone(search_opts)
+            self.assertNotIn('tenant_id', search_opts)
+            self.assertEqual('fake', search_opts['project_id'])
+            return [fakes.stub_instance_obj(100)]
+
+        req = self.req('/fake/servers?tenant_id=newfake',
+                       use_admin_context=True)
+        with mock.patch.object(compute_api.API, 'get_all') as mock_get:
+            mock_get.side_effect = fake_get_all
+            servers = self.controller.index(req)['servers']
+        self.assertEqual(len(servers), 1)
+
     def test_all_tenants_param_normal(self):
         def fake_get_all(context, search_opts=None, **kwargs):
             self.assertNotIn('project_id', search_opts)