diff --git a/node/utils/ExportHtml.js b/node/utils/ExportHtml.js
index 4cd4bbee..dce156ec 100644
--- a/node/utils/ExportHtml.js
+++ b/node/utils/ExportHtml.js
@@ -402,10 +402,16 @@ function _escapeHTML(s)
       '>': '>',
     };
   }
-  return s.replace(re, function (c)
+  
+  s = s.replace(re, function (c)
   {
     return re.MAP[c];
   });
+  
+  return s.replace(/[^\x21-\x7E\s\t\n\r]/g, function(c)
+  {
+    return "&#" +c.charCodeAt(0) + ";"
+  });
 }
 
 // copied from ACE