diff --git a/_includes/sidebar.html b/_includes/sidebar.html
index 3bb03a6..1b0814c 100644
--- a/_includes/sidebar.html
+++ b/_includes/sidebar.html
@@ -15,7 +15,7 @@
         {% if start == '/' %}
           {% assign avatar_url = avatar_url | prepend: site.baseurl %}
         {% endif %}
-        <img src="{{ avatar_url }}">
+        <img src="{{ avatar_url }}" alt="avatar">
       </a>
     </div>