diff --git a/glotaran/model/model.py b/glotaran/model/model.py
index 764f5703f..8ae81139d 100644
--- a/glotaran/model/model.py
+++ b/glotaran/model/model.py
@@ -200,7 +200,7 @@ def _add_dataset_type(self):
         self._add_model_item("dataset", dataset_model_type)
 
     def as_dict(self) -> dict:
-        model_dict = {'default-megacomplex': self.default_megacomplex}
+        model_dict = {"default-megacomplex": self.default_megacomplex}
         for name in self._model_items:
             items = getattr(self, name)
             if len(items) == 0: