diff --git a/README.md b/README.md
index 31fafa7..5b743e9 100644
--- a/README.md
+++ b/README.md
@@ -59,10 +59,12 @@ with my_vcr.use_cassette('test.json'):
 Otherwise, you can override options each time you use a cassette.  
 
 ```python
-with my_vcr.use_cassette('test.yml', serializer='json'):
+with vcr.use_cassette('test.yml', serializer='json'):
     # your http code here
 ```
 
+Note: Per-cassette overrides take precedence over the global config.
+
 ## Advanced Features
 
 If you want, VCR.py can return information about the cassette it is