diff --git a/app/src/services/sanitize-transformer.es6 b/app/src/services/sanitize-transformer.es6
index 07f877960..ab80c133c 100644
--- a/app/src/services/sanitize-transformer.es6
+++ b/app/src/services/sanitize-transformer.es6
@@ -334,6 +334,7 @@ const Preset = {
         'charset',
         'checked',
         'classid',
+        'class',
         'classname',
         'clear',
         'colspan',