diff --git a/src/main/java/com/ntlab/irisserver/resources/GameRest.java b/src/main/java/com/ntlab/irisserver/resources/GameRest.java
index cd769b2..734c312 100644
--- a/src/main/java/com/ntlab/irisserver/resources/GameRest.java
+++ b/src/main/java/com/ntlab/irisserver/resources/GameRest.java
@@ -10,6 +10,7 @@
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
@@ -47,7 +48,7 @@
         Game game = room.getGame();
         Map<Integer, String> keywordList = game.getKeywords();
         List<Integer> map = game.getMap();
-        List<String> keywords = null;
+        List<String> keywords = new ArrayList<>();
         for(int i=0; i<16; i++){
             keywords.add(keywordList.get(map.get(i)));
         }