diff --git a/main.py b/main.py
index f5f8274..6abf6b0 100644
--- a/main.py
+++ b/main.py
@@ -438,15 +438,19 @@ def generate_compliant_zugferd_cii(data):
         ET.SubElement(contract_ref, f"{{{RAM}}}IssuerAssignedID").text = str(data["contract_id"]).strip()
 
     header_deliv = ET.SubElement(trade_trans, f"{{{RAM}}}ApplicableHeaderTradeDelivery")
-    if data.get("delivery_note_id") and str(data["delivery_note_id"]).strip() != "":
-        dn_ref = ET.SubElement(header_deliv, f"{{{RAM}}}DeliveryNoteReferencedDocument")
-        ET.SubElement(dn_ref, f"{{{RAM}}}IssuerAssignedID").text = str(data["delivery_note_id"]).strip()
-        
     if data.get("delivery_date"):
         act_deliv = ET.SubElement(header_deliv, f"{{{RAM}}}ActualDeliverySupplyChainEvent")
         occ_date = ET.SubElement(act_deliv, f"{{{RAM}}}OccurrenceDateTime")
         ET.SubElement(occ_date, f"{{{UDT}}}DateTimeString", {"format": "102"}).text = format_cii_date(data["delivery_date"])
 
+    # HINWEIS: "DeliveryNoteReferencedDocument" existiert im EN16931/Factur-X-Schema NICHT
+    # (im offiziellen XSD nicht vorhanden). Das korrekte, schema-konforme Element für eine
+    # Lieferschein-/Lieferavis-Referenz ist "DespatchAdviceReferencedDocument" und muss laut
+    # XSD-Sequenz NACH ActualDeliverySupplyChainEvent stehen.
+    if data.get("delivery_note_id") and str(data["delivery_note_id"]).strip() != "":
+        dn_ref = ET.SubElement(header_deliv, f"{{{RAM}}}DespatchAdviceReferencedDocument")
+        ET.SubElement(dn_ref, f"{{{RAM}}}IssuerAssignedID").text = str(data["delivery_note_id"]).strip()
+
     header_settle = ET.SubElement(trade_trans, f"{{{RAM}}}ApplicableHeaderTradeSettlement")
     ET.SubElement(header_settle, f"{{{RAM}}}InvoiceCurrencyCode").text = "EUR"