--- a/src/pyams_sequence/widget/templates/references-list-input.pt	Thu Jun 28 08:43:43 2018 +0200
+++ b/src/pyams_sequence/widget/templates/references-list-input.pt	Fri Jun 29 18:12:36 2018 +0200
@@ -8,7 +8,7 @@
 		tal:attributes="data-ams-select2-target view/name"></i>
 	<div class="select2-parent"
 		 tal:omit-tag="view/required">
-		<input type="hidden" autocomplete="off"
+		<input type="hidden" autocomplete="off" multiple="multiple"
 			data-ams-select2-minimum-input-length="2"
 			data-ams-select2-allow-clear="true"
 			data-ams-select2-multiple="true"