diff --git a/frontend/server-data.rst b/frontend/server-data.rst
index 479c4ec21c2..62e60976111 100644
--- a/frontend/server-data.rst
+++ b/frontend/server-data.rst
@@ -10,7 +10,7 @@ them later in JavaScript. For example:
 
     <div class="js-user-rating"
         data-is-authenticated="{{ app.user ? 'true' : 'false' }}"
-        data-user="{{ app.user|serialize(format = 'json') }}"
+        data-user="{{ app.user|serialize(format = 'json')|e('html_attr') }}"
     >
         <!-- ... -->
     </div>