diff --git a/mixmatch/proxy.py b/mixmatch/proxy.py
index ad6b220..4ab6196 100644
--- a/mixmatch/proxy.py
+++ b/mixmatch/proxy.py
@@ -203,19 +203,16 @@ class RequestHandler(object):
         return resp
 
     def _finalize(self, response):
-        if not self.stream:
-            final_response = flask.Response(
-                response.text,
-                response.status_code
-            )
-            for key, value in response.headers.items():
-                final_response.headers[key] = value
+        if self.stream:
+            text = flask.stream_with_context(stream_response(response))
         else:
-            final_response = flask.Response(
-                flask.stream_with_context(stream_response(response)),
-                response.status_code,
-                content_type=response.headers['content-type']
-            )
+            text = response.text
+
+        final_response = flask.Response(
+            text,
+            response.status_code,
+            headers=self._prepare_headers(response.headers)
+        )
         LOG.info(format_for_log(title='Response from proxy',
                                 status_code=final_response.status_code,
                                 url=response.url,
@@ -298,8 +295,11 @@ class RequestHandler(object):
         headers = dict()
         headers['Accept'] = user_headers.get('Accept', '')
         headers['Content-Type'] = user_headers.get('Content-Type', '')
+        accepted_headers = ['openstack-api-version']
         for key, value in user_headers.items():
-            if key.lower().startswith('x-') and not is_token_header_key(key):
+            k = key.lower()
+            if ((k.startswith('x-') and not is_token_header_key(key)) or
+                    k in accepted_headers):
                 headers[key] = value
         return headers
 
diff --git a/mixmatch/tests/functional/tempest_blacklist.txt b/mixmatch/tests/functional/tempest_blacklist.txt
index e99e926..286a624 100644
--- a/mixmatch/tests/functional/tempest_blacklist.txt
+++ b/mixmatch/tests/functional/tempest_blacklist.txt
@@ -17,11 +17,6 @@ tempest.api.volume.test_volumes_list.VolumesListTestJSON.test_volume_list_detail
 tempest.api.volume.test_volumes_snapshots.VolumesSnapshotTestJSON.test_snapshot_create_with_volume_in_use
 tempest.api.image.v2.test_images.BasicOperationsImagesTest.test_deactivate_reactivate_image
 
-# These fail with Object not found because we do not handle /volume/v3/<project_id>/messages
-tempest.api.volume.admin.test_user_messages.UserMessagesTest.test_show_message
-tempest.api.volume.admin.test_user_messages.UserMessagesTest.test_list_messages
-tempest.api.volume.admin.test_user_messages.UserMessagesTest.test_delete_message
-
 # TODO(knikolla): Investigate these failures
 tempest.api.object_storage.test_container_sync_middleware.ContainerSyncMiddlewareTest
 tempest.api.compute.images.test_images_oneserver.ImagesOneServerTestJSON.test_create_image_specify_multibyte_character_image_name
diff --git a/mixmatch/tests/unit/test_request_handler.py b/mixmatch/tests/unit/test_request_handler.py
index 2cbb641..a8fba2c 100644
--- a/mixmatch/tests/unit/test_request_handler.py
+++ b/mixmatch/tests/unit/test_request_handler.py
@@ -43,14 +43,17 @@ class TestRequestHandler(BaseTest):
             'extra cheese': 'x-tra cheese',
             'y-auth-token': 'x-auth-token',
             'xauth-token': 'x-auth-token',
-            'start-x': 'startx'
+            'start-x': 'startx',
+
+            'OpenStack-API-Version': 'volume 3.0'
         }
         expected_headers = {
             'x-tra cheese': 'extra cheese',
             'x-goth-token': 'x-auth-token',
             'X-MEN': 'X MEN',
             'Accept': '',
-            'Content-Type': ''
+            'Content-Type': '',
+            'OpenStack-API-Version': 'volume 3.0'
         }
         headers = proxy.RequestHandler._prepare_headers(user_headers)
         self.assertEqual(expected_headers, headers)
diff --git a/mixmatch/tests/unit/test_volumes.py b/mixmatch/tests/unit/test_volumes.py
index 8cbbb02..0c86830 100644
--- a/mixmatch/tests/unit/test_volumes.py
+++ b/mixmatch/tests/unit/test_volumes.py
@@ -22,6 +22,69 @@ from mixmatch.model import insert, ResourceMapping
 from mixmatch.tests.unit import samples
 
 
+class TestVolumesV3(base.BaseTest):
+    def setUp(self):
+        super(TestVolumesV3, self).setUp()
+        # TODO(knikolla): load_auth_fixtures() should be done in the base
+        # class, but may conflict with the other tests which haven't been
+        # migrated to these fixtures.
+        self.load_auth_fixtures()
+
+    def _construct_url(self, auth=None, target=None, sp=None,
+                       resource_type='volumes'):
+        if not sp:
+            url = '/volume'
+        else:
+            url = self.service_providers[sp]['volume_endpoint']
+
+        if auth:
+            url = '%(url)s/v3/%(project_id)s/%(resource_type)s' % {
+                'url': url,
+                'project_id': auth.get_project_id(),
+                'resource_type': resource_type
+            }
+            if target:
+                url = '%s/%s' % (url, target)
+
+        return url
+
+    def test_get_messages(self):
+        fake_message_list = uuid.uuid4().hex
+
+        self.requests_fixture.get(
+            self._construct_url(self.auth,
+                                resource_type='messages',
+                                sp='default'),
+            request_headers=self.auth.get_headers(),
+            text=six.u(fake_message_list),
+            headers={'CONTENT-TYPE': 'application/json'}
+        )
+        response = self.app.get(
+            self._construct_url(self.auth, resource_type='messages'),
+            headers=self.auth.get_headers()
+        )
+        self.assertEqual(response.data, six.b(fake_message_list))
+
+    def test_get_message(self):
+        fake_message = uuid.uuid4().hex
+
+        self.requests_fixture.get(
+            self._construct_url(self.auth,
+                                fake_message,
+                                resource_type='messages',
+                                sp='default'),
+            request_headers=self.auth.get_headers(),
+            text=six.u(fake_message),
+            headers={'CONTENT-TYPE': 'application/json'}
+        )
+        response = self.app.get(
+            self._construct_url(self.auth, fake_message,
+                                resource_type='messages'),
+            headers=self.auth.get_headers()
+        )
+        self.assertEqual(response.data, six.b(fake_message))
+
+
 class TestVolumesV2(base.BaseTest):
     def setUp(self):
         super(TestVolumesV2, self).setUp()