diff --git a/src/includes/theme.php b/src/includes/theme.php
index f7966c0..f9e2674 100644
--- a/src/includes/theme.php
+++ b/src/includes/theme.php
@@ -10,14 +10,14 @@
   <title><?php mttinfo('title'); ?></title>
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <link rel="icon" type="image/gif" href="<?php mttinfo('theme_url'); ?>images/logo.gif">
-  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>style.css?v=<?php mttinfo('version'); ?>" media="all">
-  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>markdown.css?v=<?php mttinfo('version'); ?>" media="all">
+  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>style.css?v=<?php filever('theme', 'style.css'); ?>" media="all">
+  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>markdown.css?v=<?php filever('theme', 'markdown.css'); ?>" media="all">
   <?php if (in_array(get_mttinfo('appearance'), ['system','dark'])): ?>
-  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>dark.css?v=<?php mttinfo('version'); ?>" media="screen">
+  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>dark.css?v=<?php filever('theme', 'dark.css'); ?>" media="screen">
   <?php endif; ?>
-  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>print.css?v=<?php mttinfo('version'); ?>" media="print">
+  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>print.css?v=<?php filever('theme', 'print.css'); ?>" media="print">
   <?php if(Config::get('rtl')): ?>
-  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>style_rtl.css?v=<?php mttinfo('version'); ?>" media="all">
+  <link rel="stylesheet" type="text/css" href="<?php mttinfo('theme_url'); ?>style_rtl.css?v=<?php filever('theme', 'style_rtl.css'); ?>" media="all">
   <?php endif; ?>
   <?php do_action('theme_head_end'); ?>
 </head>
@@ -27,8 +27,8 @@
 <script type="text/javascript" src="<?php mttinfo('content_url'); ?>js/jquery.min.js?v=3.6.4"></script>
 <script type="text/javascript" src="<?php mttinfo('content_url'); ?>js/jquery-ui.min.js?v=1.13.2"></script>
 <script type="text/javascript" src="<?php mttinfo('content_url'); ?>js/jquery.ui.touch-punch.js?v=1.0.8-2"></script>
-<script type="text/javascript" src="<?php mttinfo('content_url'); ?>mytinytodo.js?v=<?php mttinfo('version'); ?>"></script>
-<script type="text/javascript" src="<?php mttinfo('content_url'); ?>mytinytodo_api.js?v=<?php mttinfo('version'); ?>"></script>
+<script type="text/javascript" src="<?php mttinfo('content_url'); ?>mytinytodo.js?v=<?php filever('content', 'mytinytodo.js'); ?>"></script>
+<script type="text/javascript" src="<?php mttinfo('content_url'); ?>mytinytodo_api.js?v=<?php filever('content', 'mytinytodo_api.js'); ?>"></script>
 
 <script type="text/javascript">
 $().ready(function(){
diff --git a/src/init.php b/src/init.php
index 22ae13e..5ccfa81 100644
--- a/src/init.php
+++ b/src/init.php
@@ -392,11 +392,7 @@ function get_unsafe_mttinfo($v)
             $_mttinfo['title'] = (Config::get('title') != '') ? Config::get('title') : __('My Tiny Todolist');
             return $_mttinfo['title'];
         case 'version':
-            if (MTT_DEBUG) {
-                $_mttinfo['version'] = mytinytodo\Version::VERSION . '-' . time();
-            } else {
-                $_mttinfo['version'] = mytinytodo\Version::VERSION;
-            }
+            $_mttinfo['version'] = mytinytodo\Version::VERSION;
             return $_mttinfo['version'];
         case 'appearance':
             $_mttinfo['appearance'] = Config::get('appearance');
@@ -471,3 +467,30 @@ function loadExtensions()
         }
     }
 }
+
+function filever(string $dir, string $filename)
+{
+    if (!MTT_DEBUG) {
+        return mttinfo('version');
+    }
+    $prefix = get_mttinfo('version'). '-'. time();
+    $path = null;
+    if ($dir == 'content') {
+        $path = MTTPATH. 'content/';
+    }
+    else if ($dir == 'theme') {
+        $path = MTTPATH. 'content/'. MTT_THEME. '/';
+    }
+    else {
+        return print($prefix. '-unknown');
+    }
+    $fullPath = $path. $filename;
+    if (!file_exists($fullPath)) {
+        return print($prefix. '-not-found');
+    }
+    $mtime = filemtime($fullPath);
+    if ($mtime === false) {
+        return print($prefix. '-no-access');
+    }
+    return print($mtime);
+}