diff --git a/README.md b/README.md
index 5be55639b..dd8688d37 100644
--- a/README.md
+++ b/README.md
@@ -58,3 +58,5 @@
 ##Memento
 **Intent:** Without violating encapsulation, capture and externalize an object's internal state so that the object can be restored to this state later.
 
+##Observer
+**Intent:** Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.