diff --git a/combo/apps/wcs/templates/combo/wcs/tracking_code_input.html b/combo/apps/wcs/templates/combo/wcs/tracking_code_input.html
index bf93aaa4..e7d8ea8d 100644
--- a/combo/apps/wcs/templates/combo/wcs/tracking_code_input.html
+++ b/combo/apps/wcs/templates/combo/wcs/tracking_code_input.html
@@ -14,7 +14,7 @@
   <div id="_cell_error_{{ cell.id }}" class="errornotice" style="display: none">
     {% trans "The tracking code could not been found." %}
   </div>
-  <input id="tracking-code" name="code" placeholder="{% trans 'ex: CNPHNTFB' %}"/>
+  <input required id="tracking-code" name="code" placeholder="{% trans 'ex: CNPHNTFB' %}"/>
   <button>{% trans 'Submit' %}</button>
   <script>
   $(function() {