diff --git a/static/app.js b/static/app.js
index 5f230d7..b1a2bd1 100644
--- a/static/app.js
+++ b/static/app.js
@@ -354,7 +354,7 @@
       '<button class="btn-del" onclick="this.parentElement.remove();renumberMorning()"><svg class="icon-sm"><use href="#icon-x"/></svg></button>';
     div.addEventListener('dragstart', dragStart);
     div.addEventListener('dragover', dragOver);
-    div.addEventListener('drop', function(e){ dragDrop(e, 'morning-list'); });
+    div.addEventListener('drop', function(e){ dragDrop.call(this, e, 'morning-list'); });
     div.addEventListener('dragend', dragEnd);
     container.appendChild(div);
     renumberMorning();
@@ -382,7 +382,7 @@
       '<input type="text" value="' + esc(improve) + '" placeholder="改进方案…">';
     div.addEventListener('dragstart', dragStart);
     div.addEventListener('dragover', dragOver);
-    div.addEventListener('drop', function(e){ dragDrop(e, 'evening-list'); });
+    div.addEventListener('drop', function(e){ dragDrop.call(this, e, 'evening-list'); });
     div.addEventListener('dragend', dragEnd);
     container.appendChild(div);
   }