diff --git a/README.md b/README.md
index 8c0fec1..4323a7e 100644
--- a/README.md
+++ b/README.md
@@ -81,7 +81,7 @@ Apply a tag to a Subscriber.
 
 ```php
 $tag_id = '99999'; // This tag must be valid for your ConvertKit account.
-$api->add_tag(tag_id, [
+$api->add_tag($tag_id, [
 			'email' => 'test@test.com'
 		]);
 ```