diff --git a/lib/SimpleSAML/XHTML/Template.php b/lib/SimpleSAML/XHTML/Template.php
index 90e6c027ec8fe66f9ea1d151e0fa37ca52a44774..d6fbf79e707af668eee09398dbeb7048991dc810 100644
--- a/lib/SimpleSAML/XHTML/Template.php
+++ b/lib/SimpleSAML/XHTML/Template.php
@@ -160,8 +160,9 @@ class Template extends Response
 
         $tag = $this->configuration->getVersion();
         if ($tag === 'master') {
-            $tag = substr(hash('md5', filemtime($file)), 0, 5);
+            $tag = filemtime($file);
         }
+        $tag = substr(hash('md5', $tag), 0, 5);
         return $this->configuration->getBasePath().'assets/'.$asset.'?tag='.$tag;
     }