diff --git a/bibtexbrowser.php b/bibtexbrowser.php
index e4a1e95..2110055 100755
--- a/bibtexbrowser.php
+++ b/bibtexbrowser.php
@@ -243,10 +243,11 @@ function _zetDB($bibtex_filenames) {
     $ext = pathinfo($bib, PATHINFO_EXTENSION);
     // this is a security protection
     if (BIBTEXBROWSER_LOCAL_BIB_ONLY && (!file_exists($bib) || strcasecmp($ext, 'bib') != 0)) {
-
-     // to automate dectection of faulty links with tools such as webcheck
-     header('HTTP/1.1 404 Not found');
-     die('<b>the bib file '.$bib.' does not exist !</b>');
+      // to automate dectection of faulty links with tools such as webcheck
+      header('HTTP/1.1 404 Not found');
+      // escape $bib to prevent XSS
+      $escapedBib = htmlEntities($bib, ENT_QUOTES);
+      die('<b>the bib file '.$escapedBib.' does not exist !</b>');
     }
   } // end for each