diff --git a/app/src/main/java/org/ntlab/irisclient/resources/GameRest.java b/app/src/main/java/org/ntlab/irisclient/resources/GameRest.java
index abcae65..6c22ade 100644
--- a/app/src/main/java/org/ntlab/irisclient/resources/GameRest.java
+++ b/app/src/main/java/org/ntlab/irisclient/resources/GameRest.java
@@ -122,6 +122,7 @@
 
     //-----------------------------------------------
     // 現在のターンで開くカードのcnoを送信するメソッド
+    @FormUrlEncoded
     @PUT("rooms/{rid}/game/turns/{tno}/openlist")
     Call<Void> setOpenList(
             @Path("rid") String rid,