diff --git a/koki/koryo.js b/koki/koryo.js
index 9eb0ff2..0eaf8ad 100644
--- a/koki/koryo.js
+++ b/koki/koryo.js
@@ -88,9 +88,8 @@
 		if (!judge[i]){
 		    judge[i] = true;
 		    alert("スタンプゲット!!");
-		    let img = [];
-		    img[i] = document.getElementById('image${i}');
-		    img[i].src = "sengoku.png";
+		    if (let img = document.getElementById('image${i}'))
+			img.src = "sengoku.png";
 		}
 	    }
 	}