diff --git a/_includes/head.html b/_includes/head.html
index 35ee55f..f27941a 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -96,11 +96,12 @@
     <link rel="stylesheet" href="{{ site.baseurl }}/assets/css/syntax.css">
   {% endif %}
 
-
+  <!-- jquery -->
   <link rel="preload" as="script"
     href="https://cdn.jsdelivr.net/npm/jquery@3.4.1/dist/jquery.min.js"
     integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous">
 
+  <!-- popper -->
   <link rel="preload" as="script"
     href="https://cdn.jsdelivr.net/npm/popper.js@1.15.0/dist/umd/popper.min.js"
     integrity="sha256-fTuUgtT7O2rqoImwjrhDgbXTKUwyxxujIMRIK7TbuNU=" crossorigin>
@@ -113,7 +114,7 @@
   </script>
 
   <script src="https://cdn.jsdelivr.net/npm/popper.js@1.15.0/dist/umd/popper.min.js"
-    integrity="sha256-fTuUgtT7O2rqoImwjrhDgbXTKUwyxxujIMRIK7TbuNU=" crossorigin="anonymous" async></script>
+    integrity="sha256-fTuUgtT7O2rqoImwjrhDgbXTKUwyxxujIMRIK7TbuNU=" crossorigin="anonymous"></script>
 
   <script src="https://cdn.jsdelivr.net/npm/bootstrap@4.0.0/dist/js/bootstrap.min.js"
     integrity="sha256-5+02zu5UULQkO7w1GIr6vftCgMfFdZcAHeDtFnKZsBs=" crossorigin="anonymous" async></script>