diff --git a/tools/ws.htm b/tools/ws.htm
index 22af3d8e7..f502dd8de 100644
--- a/tools/ws.htm
+++ b/tools/ws.htm
@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <title>Piwigo web API (web-services) explorer</title>
 
-  <link rel="stylesheet" href="http://cdn.jsdelivr.net/tiptip/1.3/tipTip.css">
+  <link rel="stylesheet" href="//cdn.jsdelivr.net/tiptip/1.3/tipTip.css">
 
   <style>
   /* BEGIN CSS RESET
@@ -245,8 +245,8 @@
   Copyright &copy; 2002-2013 <a href="http://piwigo.org">Piwigo Team</a>
 </div> <!-- the_footer -->
 
-<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
-<script src="https://cdn.jsdelivr.net/tiptip/1.3/jquery.tipTip.minified.js"></script>
+<script src="//code.jquery.com/jquery-1.9.1.min.js"></script>
+<script src="//cdn.jsdelivr.net/tiptip/1.3/jquery.tipTip.minified.js"></script>
 
 <script>
 // global vars
@@ -571,4 +571,4 @@ function invokeMethod(methodName, newWindow) {
 </script>
 
 </body>
-</html>
\ No newline at end of file
+</html>