diff --git a/API.md b/API.md
index 13d5da2b7..2a2b517d7 100755
--- a/API.md
+++ b/API.md
@@ -93,7 +93,7 @@ Second, the value is validated against the defined schema:
 const { error, value } = schema.validate({ a: 'a string' });
 ```
 
-If the input is valid, then the `error` will be `null`. If the input is invalid, `error` is assigned
+If the input is valid, then the `error` will be `undefined`. If the input is invalid, `error` is assigned
 a [`ValidationError`](https://github.com/hapijs/joi/blob/master/API.md#validationerror) object
 providing more information.