diff --git a/keystoneauth1/fixture/keystoneauth_betamax.py b/keystoneauth1/fixture/keystoneauth_betamax.py
index 724d217d..38afd0ab 100644
--- a/keystoneauth1/fixture/keystoneauth_betamax.py
+++ b/keystoneauth1/fixture/keystoneauth_betamax.py
@@ -28,16 +28,26 @@ class BetamaxFixture(fixtures.Fixture):
 
     def __init__(self, cassette_name, cassette_library_dir=None,
                  serializer=None, record=False,
-                 pre_record_hook=hooks.pre_record_hook):
+                 pre_record_hook=hooks.pre_record_hook,
+                 serializer_name=None):
         self.cassette_library_dir = cassette_library_dir
         self.record = record
         self.cassette_name = cassette_name
-        if not serializer:
+        if not (serializer or serializer_name):
             serializer = yaml_serializer.YamlJsonSerializer
+            serializer_name = serializer.name
+        if serializer:
+            betamax.Betamax.register_serializer(serializer)
         self.serializer = serializer
-        betamax.Betamax.register_serializer(serializer)
+        self._serializer_name = serializer_name
         self.pre_record_hook = pre_record_hook
 
+    @property
+    def serializer_name(self):
+        if self.serializer:
+            return self.serializer.name
+        return self._serializer_name
+
     def setUp(self):
         super(BetamaxFixture, self).setUp()
         self.mockpatch = mock.patch.object(
@@ -70,8 +80,7 @@ def _construct_session_with_betamax(fixture, session_obj=None):
     if fixture.record in ['once', 'all', 'new_episodes']:
         record = fixture.record
 
-    if fixture.serializer:
-        serializer = fixture.serializer.name
+    serializer = fixture.serializer_name
 
     fixture.recorder.use_cassette(fixture.cassette_name,
                                   serialize_with=serializer,
diff --git a/keystoneauth1/tests/unit/test_betamax_fixture.py b/keystoneauth1/tests/unit/test_betamax_fixture.py
index a1632ec9..f1b03cce 100644
--- a/keystoneauth1/tests/unit/test_betamax_fixture.py
+++ b/keystoneauth1/tests/unit/test_betamax_fixture.py
@@ -12,9 +12,12 @@
 
 import testtools
 
+import betamax
 from betamax import exceptions
+import mock
 
 from keystoneauth1.fixture import keystoneauth_betamax
+from keystoneauth1.fixture import serializer
 from keystoneauth1.fixture import v2 as v2Fixtures
 from keystoneauth1.identity import v2
 from keystoneauth1 import session
@@ -58,3 +61,45 @@ class TestBetamaxFixture(testtools.TestCase):
             tenant_name=self.TEST_TENANT_NAME)
         s = session.Session()
         self.assertRaises(exceptions.BetamaxError, s.get_token, auth=plugin)
+
+
+class TestBetamaxFixtureSerializerBehaviour(testtools.TestCase):
+    """Test the fixture's logic, not its monkey-patching.
+
+    The setUp method of our BetamaxFixture monkey-patches the function to
+    construct a session. We don't need to test that particular bit of logic
+    here so we do not need to call useFixture in our setUp method.
+    """
+
+    @mock.patch.object(betamax.Betamax, 'register_serializer')
+    def test_can_pass_custom_serializer(self, register_serializer):
+        serializer = mock.Mock()
+        serializer.name = 'mocked-serializer'
+        fixture = keystoneauth_betamax.BetamaxFixture(
+            cassette_name='fake',
+            cassette_library_dir='keystoneauth1/tests/unit/data',
+            serializer=serializer,
+        )
+
+        register_serializer.assert_called_once_with(serializer)
+        self.assertIs(serializer, fixture.serializer)
+        self.assertEqual('mocked-serializer', fixture.serializer_name)
+
+    def test_can_pass_serializer_name(self):
+        fixture = keystoneauth_betamax.BetamaxFixture(
+            cassette_name='fake',
+            cassette_library_dir='keystoneauth1/tests/unit/data',
+            serializer_name='json',
+        )
+
+        self.assertIsNone(fixture.serializer)
+        self.assertEqual('json', fixture.serializer_name)
+
+    def test_no_serializer_options_provided(self):
+        fixture = keystoneauth_betamax.BetamaxFixture(
+            cassette_name='fake',
+            cassette_library_dir='keystoneauth1/tests/unit/data',
+        )
+
+        self.assertIs(serializer.YamlJsonSerializer, fixture.serializer)
+        self.assertEqual('yamljson', fixture.serializer_name)