diff --git a/app/src/main/java/org/ntlab/acanthus_client/entities/Position.java b/app/src/main/java/org/ntlab/acanthus_client/entities/Position.java
index 70e748d..c194913 100644
--- a/app/src/main/java/org/ntlab/acanthus_client/entities/Position.java
+++ b/app/src/main/java/org/ntlab/acanthus_client/entities/Position.java
@@ -2,14 +2,17 @@
 
 //-----------------------------------------------------------------
 // ペン座標
-public class Position {
+public class Position implements Comparable {
     private int i;
     private Float x;
     private Float y;
 
     //-----------------------------------------------------------------
     // getter
-    public int getI(){return this.i;};
+    public int getI() {
+        return this.i;
+    }
+
     public Float getX() {
         return this.x;
     }
@@ -25,4 +28,11 @@
         this.x = x;
         this.y = y;
     }
+
+    //-----------------------------------------------------------------
+    //
+    @Override
+    public int compareTo(Object o) {
+        return 0;
+    }
 }