diff --git a/_layouts/default.html b/_layouts/default.html
index beb75649..2eee5bb8 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -44,11 +44,11 @@
 	<meta name="theme-color" content="#ffffff">
 
 	<!-- CSS stylesheets -->
-	<link href="css/bootstrap.min.css" rel="stylesheet">
-	<link href="css/flag-icon.min.css" rel="stylesheet">
-	<link href="css/fontawesome-all.min.css" rel="stylesheet">
-	<link href="css/sortable-theme-bootstrap.css" rel="stylesheet" />
-	<link href="css/custom.css?v=1" rel="stylesheet">
+	<link href="css/bootstrap.min.css?v=4" rel="stylesheet">
+	<link href="css/flag-icon.min.css?v=4" rel="stylesheet">
+	<link href="css/fontawesome-all.min.css?v=4" rel="stylesheet">
+	<link href="css/sortable-theme-bootstrap.css?v=4" rel="stylesheet" />
+	<link href="css/custom.css?v=4" rel="stylesheet">
 
 	<!--[if lt IE 9]>
       <script src="js/html5shiv.min.js"></script>
@@ -181,10 +181,10 @@
 </div>
 
 <!-- add jQuery, Popper, Bootstrap, Sortable, and tooltip libraries  -->
-<script src="js/jquery-3.3.1.min.js"></script>
-<script src="js/popper.min.js"></script>
-<script src="js/bootstrap.min.js"></script>
-<script src="js/sortable.min.js"></script>
+<script src="js/jquery-3.3.1.min.js?v=4"></script>
+<script src="js/popper.min.js?v=4"></script>
+<script src="js/bootstrap.min.js?v=4"></script>
+<script src="js/sortable.min.js?v=4"></script>
 <script>
 	$(function() {
 		$("[data-toggle='tooltip']").tooltip();