diff --git a/app/views/layouts/error.html.erb b/app/views/layouts/error.html.erb
index 421396e0..48a585e4 100644
--- a/app/views/layouts/error.html.erb
+++ b/app/views/layouts/error.html.erb
@@ -17,10 +17,10 @@
 
   <%= stylesheet_link_tag 'instiki' unless @inline_style %>
 
-  <style type="text/css">
+  <style type="text/css"><!--/*--><![CDATA[/*><!--*/
     <%= @style_additions %>
     <%= @web ? @web.additional_style : '' %>
-  </style>
+  /*]]>*/--></style>
 </head>
 
 <body>
diff --git a/app/views/wiki/tex.rhtml b/app/views/wiki/tex.rhtml
index dfee856c..02095fff 100644
--- a/app/views/wiki/tex.rhtml
+++ b/app/views/wiki/tex.rhtml
@@ -102,6 +102,7 @@
 \re@DeclareMathSymbol{\swArr}{\mathrel}{symbolsC}{119}
 \re@DeclareMathSymbol{\nequiv}{\mathrel}{symbolsC}{46}
 \re@DeclareMathSymbol{\Perp}{\mathrel}{symbolsC}{121}
+\re@DeclareMathSymbol{\Vbar}{\mathrel}{symbolsC}{121}
 \makeatother
 
 % Widecheck
