diff --git a/htdocs/externalsite/frames.php b/htdocs/externalsite/frames.php
index 3832408818090ba28744676dc07727da1bc10efc..c0b5cf92e7e53b75daa6b5f5fce91afb41e22b27 100644
--- a/htdocs/externalsite/frames.php
+++ b/htdocs/externalsite/frames.php
@@ -58,7 +58,7 @@ print "
 
 <noframes>
 <body>
-	<br><div class="center">
+	<br><div class=\"center\">
 	Sorry, your browser is too old or not correctly configured to view this area.<br>
 	Your browser must support frames.<br>
 	</div>