diff --git a/l10n_br_nfe/models/document.py b/l10n_br_nfe/models/document.py
index abdfcc7092b0..a7f82005e0bc 100644
--- a/l10n_br_nfe/models/document.py
+++ b/l10n_br_nfe/models/document.py
@@ -849,7 +849,7 @@ def _check_product_default_code(self):
     @api.constrains("document_date", "document_key", "state_edoc")
     def _check_document_date_key(self):
         for rec in self:
-            if rec.document_key:
+            if rec.document_key and rec.document_date:
                 key_date_str = rec.document_key[2:6]
                 key_date = datetime.strptime(key_date_str, "%y%m")