diff --git a/observer/README.md b/observer/README.md
index 2ac98c401..3b3fcd2c5 100644
--- a/observer/README.md
+++ b/observer/README.md
@@ -38,6 +38,7 @@ Use the Observer pattern in any of the following situations
 * [java.util.Observer](http://docs.oracle.com/javase/8/docs/api/java/util/Observer.html)
 * [java.util.EventListener](http://docs.oracle.com/javase/8/docs/api/java/util/EventListener.html)
 * [javax.servlet.http.HttpSessionBindingListener](http://docs.oracle.com/javaee/7/api/javax/servlet/http/HttpSessionBindingListener.html)
+* [RxJava](https://github.com/ReactiveX/RxJava)
 
 ## Credits