diff --git a/dna_features_viewer/BiopythonTranslator/BiopythonTranslatorBase.py b/dna_features_viewer/BiopythonTranslator/BiopythonTranslatorBase.py
index 74ff3f9..9988708 100644
--- a/dna_features_viewer/BiopythonTranslator/BiopythonTranslatorBase.py
+++ b/dna_features_viewer/BiopythonTranslator/BiopythonTranslatorBase.py
@@ -86,7 +86,7 @@ def translate_record(self, record, record_class=None, filetype=None):
         filtered_features = self.compute_filtered_features(record.features)
         return record_class(
             sequence_length=len(record),
-            sequence=str(record.seq) if record.seq.defined else None,
+            sequence=str(record.seq) if record.seq else None,
             features=[
                 self.translate_feature(feature)
                 for feature in filtered_features