diff --git a/tests/unit/test_serialize.py b/tests/unit/test_serialize.py
new file mode 100644
index 0000000..a4ccd73
--- /dev/null
+++ b/tests/unit/test_serialize.py
@@ -0,0 +1,21 @@
+import pytest
+from vcr.serialize import deserialize
+from vcr.serializers import yamlserializer, jsonserializer
+
+def test_deserialize_old_yaml_cassette():
+    with open('tests/fixtures/migration/old_cassette.yaml', 'r') as f:
+        with pytest.raises(ValueError):
+            deserialize(f.read(), yamlserializer)
+
+def test_deserialize_old_json_cassette():
+    with open('tests/fixtures/migration/old_cassette.json', 'r') as f:
+        with pytest.raises(ValueError):
+            deserialize(f.read(), jsonserializer)
+
+def test_deserialize_new_yaml_cassette():
+    with open('tests/fixtures/migration/new_cassette.yaml', 'r') as f:
+        deserialize(f.read(), yamlserializer)
+
+def test_deserialize_new_json_cassette():
+    with open('tests/fixtures/migration/new_cassette.json', 'r') as f:
+        deserialize(f.read(), jsonserializer)