diff --git a/src/kiri-mode/cam/tools.js b/src/kiri-mode/cam/tools.js
index 52e65b8a..e5764d5a 100644
--- a/src/kiri-mode/cam/tools.js
+++ b/src/kiri-mode/cam/tools.js
@@ -248,6 +248,7 @@ gapp.register("kiri-mode.cam.tools", (root, exports) => {
             } else {
                 name = `${name} 2`;
             }
+            clone.id = Date.now();
             clone.number = maxTool + 1;
             clone.name = name;
             editTools.push(clone);