diff --git a/MuoVErsi/sources/base.py b/MuoVErsi/sources/base.py
index 15ddce6..d8962a1 100644
--- a/MuoVErsi/sources/base.py
+++ b/MuoVErsi/sources/base.py
@@ -370,7 +370,7 @@ class Trip(Base):
     __tablename__ = 'trips'
 
     id: Mapped[int] = mapped_column(primary_key=True)
-    orig_id: Mapped[Optional[str]]
+    orig_id: Mapped[str]
     dest_text: Mapped[str]
     number: Mapped[int]
     orig_dep_date: Mapped[date]
diff --git a/alembic/versions/1f2c7b1eec8b_add_source_field_to_trips.py b/alembic/versions/1f2c7b1eec8b_add_source_field_to_trips.py
index d657cfc..d95580c 100644
--- a/alembic/versions/1f2c7b1eec8b_add_source_field_to_trips.py
+++ b/alembic/versions/1f2c7b1eec8b_add_source_field_to_trips.py
@@ -18,9 +18,6 @@
 
 def upgrade() -> None:
     op.add_column('trips', sa.Column('source', sa.String(), server_default='treni', nullable=False))
-    op.alter_column('trips', 'orig_id',
-               existing_type=sa.VARCHAR(),
-               nullable=True)
     op.drop_constraint('trains_codOrigine_numeroTreno_dataPartenzaTreno_key', 'trips', type_='unique')
 
     # update foreign key of stop_times.trip_id to cascade on delete
@@ -30,16 +27,13 @@ def upgrade() -> None:
     # remove duplicates of source, number, orig_dep_date from trips table
     op.execute('DELETE FROM trips WHERE id IN (SELECT id FROM (SELECT id, ROW_NUMBER() OVER (partition BY source, number, orig_dep_date ORDER BY id) AS rnum FROM trips) t WHERE t.rnum > 1);')
 
-    op.create_unique_constraint(None, 'trips', ['source', 'number', 'orig_dep_date'])
+    op.create_unique_constraint('trips_source_number_orig_dep_date_key', 'trips', ['source', 'number', 'orig_dep_date'])
 
 
 
 def downgrade() -> None:
-    op.drop_constraint(None, 'trips', type_='unique')
+    op.drop_constraint('trips_source_number_orig_dep_date_key', 'trips', type_='unique')
     op.create_unique_constraint('trains_codOrigine_numeroTreno_dataPartenzaTreno_key', 'trips', ['orig_id', 'number', 'orig_dep_date'])
-    op.alter_column('trips', 'orig_id',
-               existing_type=sa.VARCHAR(),
-               nullable=False)
     op.drop_column('trips', 'source')
     op.drop_constraint('stop_times_trip_id_fkey', 'stop_times', type_='foreignkey')
     op.create_foreign_key('stop_times_train_id_fkey', 'stop_times', 'trips', ['trip_id'], ['id'])