diff --git a/api/models/dataset.py b/api/models/dataset.py
index 07a2849df9..c49de58120 100644
--- a/api/models/dataset.py
+++ b/api/models/dataset.py
@@ -59,7 +59,7 @@ class Dataset(Base):
     created_at = mapped_column(db.DateTime, nullable=False, server_default=func.current_timestamp())
     updated_by = mapped_column(StringUUID, nullable=True)
     updated_at = mapped_column(db.DateTime, nullable=False, server_default=func.current_timestamp())
-    embedding_model: Mapped[str] = mapped_column(db.String(255), nullable=True)
+    embedding_model: Mapped[Optional[str]] = mapped_column(db.String(255), nullable=True)
     embedding_model_provider: Mapped[Optional[str]] = mapped_column(db.String(255), nullable=True)
     collection_binding_id = mapped_column(StringUUID, nullable=True)
     retrieval_model = mapped_column(JSONB, nullable=True)