diff --git a/README.md b/README.md
index 70f5c76..23d7259 100644
--- a/README.md
+++ b/README.md
@@ -127,8 +127,8 @@ object(stdClass)#26 (2) {
 For usage examples on each API endpoint, head over to our official documentation 
 pages. 
 
-This SDK includes a [Message Builder](src/Mailgun/Messages/README.md) and 
-[Batch Message](src/Mailgun/Messages/README.md) component.
+This SDK includes a [Message Builder](src/Mailgun/Messages/README.md), 
+[Batch Message](src/Mailgun/Messages/README.md) and [Opt-In Handler](src/Mailgun/Lists/README.md) component.
 
 Message Builder allows you to quickly create the array of parameters, required 
 to send a message, by calling a methods for each parameter.