diff --git a/nova/compute/api.py b/nova/compute/api.py
index 8cf7a52a0bcc..c3a552313d13 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -4282,12 +4282,17 @@ class API(base.Base):
         def detach_volume(self, context, instance, bdms):
             self._local_cleanup_bdm_volumes(bdms, instance, context)
 
-        try:
-            self.volume_api.begin_detaching(context, volume['id'])
-        except exception.InvalidInput as exc:
-            raise exception.InvalidVolume(reason=exc.format_message())
         bdms = [objects.BlockDeviceMapping.get_by_volume_id(
                 context, volume['id'], instance.uuid)]
+        # The begin_detaching() call only works with in-use volumes,
+        # which will not be the case for volumes attached to a shelved
+        # offloaded server via the attachments API since those volumes
+        # will have `reserved` status.
+        if not bdms[0].attachment_id:
+            try:
+                self.volume_api.begin_detaching(context, volume['id'])
+            except exception.InvalidInput as exc:
+                raise exception.InvalidVolume(reason=exc.format_message())
         self._record_action_start(
             context, instance,
             instance_actions.DETACH_VOLUME)
diff --git a/nova/tests/functional/test_servers.py b/nova/tests/functional/test_servers.py
index 7d8bf5e06aa0..4238a7f7426a 100644
--- a/nova/tests/functional/test_servers.py
+++ b/nova/tests/functional/test_servers.py
@@ -1220,19 +1220,16 @@ class ServerTestV220(ServersTestBase):
             self.assertIsNone(attach_response['device'])
 
         # Test detach volume
-        with test.nested(mock.patch.object(volume.cinder.API,
-                                           'begin_detaching'),
-                         mock.patch.object(objects.BlockDeviceMappingList,
+        with test.nested(mock.patch.object(objects.BlockDeviceMappingList,
                                            'get_by_instance_uuid'),
                          mock.patch.object(compute_api.API,
                                            '_local_cleanup_bdm_volumes')
-                         ) as (mock_check, mock_get_bdms, mock_clean_vols):
+                         ) as (mock_get_bdms, mock_clean_vols):
 
             mock_get_bdms.return_value = fake_bdms
             attachment_id = mock_get_bdms.return_value[0]['volume_id']
             self.api.api_delete('/servers/%s/os-volume_attachments/%s' %
                             (server_id, attachment_id))
-            self.assertTrue(mock_check.called)
             self.assertTrue(mock_clean_vols.called)
 
         self._delete_server(server_id)
diff --git a/nova/tests/unit/compute/test_compute.py b/nova/tests/unit/compute/test_compute.py
index 1d57f07df3e8..3246db54fa8f 100644
--- a/nova/tests/unit/compute/test_compute.py
+++ b/nova/tests/unit/compute/test_compute.py
@@ -10804,8 +10804,7 @@ class ComputeAPITestCase(BaseTestCase):
         self.compute_api._detach_volume_shelved_offloaded(self.context,
                                                           instance,
                                                           volume)
-        mock_begin_detaching.assert_called_once_with(self.context,
-                                                     volume['id'])
+        mock_begin_detaching.assert_not_called()
         self.assertTrue(mock_local_cleanup.called)
 
     @mock.patch.object(nova.volume.cinder.API, 'begin_detaching',