diff --git a/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/ListBox_asHTML.xml b/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/ListBox_asHTML.xml
index 90fe2cb7f73419d3f8398882d94334cca2356f65..42e19da301df9c63f6df2a96794c621987f689ff 100644
--- a/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/ListBox_asHTML.xml
+++ b/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/ListBox_asHTML.xml
@@ -503,6 +503,8 @@
                 <span i18n:translate="" i18n:domain="ui">\n
                   No result.\n
                 </span>\n
+                <input type="hidden" value="1" name="listbox_empty:boolean"\n
+                       tal:attributes="name string:${field_prefix}${field_id}_empty:boolean" />\n
               </td>\n
             </tr>\n
           </tbody>\n
diff --git a/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision b/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision
index 87b98496d9677897f03e0d6f8b216e69e05c69d7..b29e8d2b2be279ea7c2e24283d29ecb956f7a1bd 100644
--- a/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision
+++ b/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision
@@ -1 +1 @@
-1089
\ No newline at end of file
+1090
\ No newline at end of file
diff --git a/product/ERP5Form/ListBox.py b/product/ERP5Form/ListBox.py
index 089017a2367b24afea0c2e424f683b1006bd89ad..bc84c6c5fcc636b1bb4755c5d154acdc7b76a0aa 100644
--- a/product/ERP5Form/ListBox.py
+++ b/product/ERP5Form/ListBox.py
@@ -2762,11 +2762,15 @@ class ListBoxValidator(Validator.Validator):
 
         result = {}
         error_result = {}
-        try:
-          listbox_uids = REQUEST['%s_uid' % field.id]
-        except KeyError:
-          raise KeyError('Field %s is not present in request object.'
-                         % field.id)
+        listbox_empty = REQUEST.get('%s_empty' % field.id, False)
+        if listbox_empty:
+          listbox_uids = []
+        else:
+          try:
+            listbox_uids = REQUEST['%s_uid' % field.id]
+          except KeyError:
+            raise KeyError('Field %s is not present in request object.'
+                           % field.id)
         select = field.get_value('select')
         if select:
           selected_uid_set = set(REQUEST.get('uids', ()))