diff --git a/src/main/java/com/ntlab/irisserver/entities/Room.java b/src/main/java/com/ntlab/irisserver/entities/Room.java
index 1deb1f7..c94e788 100644
--- a/src/main/java/com/ntlab/irisserver/entities/Room.java
+++ b/src/main/java/com/ntlab/irisserver/entities/Room.java
@@ -7,7 +7,7 @@
 import java.util.*;
 
 
-public class Room {
+public class Room implements IStateListener {
         @JsonProperty("rid")
         public String rid;
         //String rid = null;