diff --git a/README.md b/README.md
index 6f882d0..6eea8d4 100644
--- a/README.md
+++ b/README.md
@@ -232,7 +232,7 @@ but not
   boolean: Boolean, # See http://stackoverflow.com/questions/3028243/check-if-ruby-object-is-a-boolean#answer-3028378
   array:   Array,
   object:  Hash,
-  null:    NilClass,
+  null:    NilClass
 }
 ```
 matches the JSON object