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 f311050..fc77782 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
@@ -2,7 +2,7 @@
 
 //-----------------------------------------------------------------
 // ペン座標
-public class Position implements Comparable {
+public class Position {
     private int i;
     private Float x;
     private Float y;
@@ -31,15 +31,4 @@
 
     //-----------------------------------------------------------------
     //
-    @Override
-    public int compareTo(Object o) {
-        if (o instanceof Position) {
-            if (i < ((Position) o).i) {
-                return -1;
-            } else if (i > ((Position) o).i) {
-                return 1;
-            }
-        }
-        return 0;
-    }
 }