diff --git a/invenio_oaiserver/verbs.py b/invenio_oaiserver/verbs.py
index f621170..e5f9f50 100644
--- a/invenio_oaiserver/verbs.py
+++ b/invenio_oaiserver/verbs.py
@@ -120,6 +120,7 @@ class ListIdentifiers(OAISchema):
         from_ = DateTime(
             format="permissive",
             metadata={"load_from": "from", "data_key": "from", "dump_to": "from"},
+            data_key="from"
         )
         until = DateTime(format="permissive")
         set = fields.Str()