diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoice.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoice.tt
index 89e1f0e04c..5a1d654ab5 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoice.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoice.tt
@@ -80,7 +80,7 @@
         <fieldset class="rows">
             <ol>
             <li>
-                <label for="shipmentdate">Invoice number:</label>
+                <label for="shipmentdate" class="required">Invoice number:</label>
                 <input type="text" id="invoicenumber" name="invoicenumber" value="[% invoicenumber %]" class="required" required="required"/>
                 <span class="required">Required</span>
             </li>
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoices.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoices.tt
index 9755488a89..22cc770692 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoices.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoices.tt
@@ -182,7 +182,7 @@ $(document).ready(function() {
                         <tbody>
                         </tbody>
                     </table></li>
-                    <li><label for="merge_invoicenumber">Invoice number:</label>
+                    <li><label for="merge_invoicenumber" class="required">Invoice number:</label>
                             <input type="text" size="10" id="merge_invoicenumber" name="invoicenumber" value="" class="required" required="required" />
                             <span class="required">Required</span>
                             </li>