diff --git a/worblehat/devscripts/seed_test_data.py b/worblehat/devscripts/seed_test_data.py
index 567be0f..02cda53 100644
--- a/worblehat/devscripts/seed_test_data.py
+++ b/worblehat/devscripts/seed_test_data.py
@@ -78,10 +78,10 @@ def main(sql_session):
     second_half = bookcase_items[half:]
 
     for item in first_half:
-        item.bookcase_shelf = seed_shelf_1
+        seed_shelf_1.items.add(item)
 
     for item in second_half:
-        item.bookcase_shelf = seed_shelf_2
+        seed_shelf_2.items.add(item)
 
     sql_session.add_all(bookcase_items)
     sql_session.commit()
diff --git a/worblehat/models/BookcaseItem.py b/worblehat/models/BookcaseItem.py
index 3a26280..e907f1f 100644
--- a/worblehat/models/BookcaseItem.py
+++ b/worblehat/models/BookcaseItem.py
@@ -41,7 +41,7 @@ class BookcaseItem(Base, UidMixin):
     amount: Mapped[int] = mapped_column(SmallInteger, default=1)
 
     fk_media_type_uid: Mapped[int] = mapped_column(ForeignKey('MediaType.uid'))
-    fk_bookcase_shelf_uid: Mapped[int | None] = mapped_column(ForeignKey('BookcaseShelf.uid'))
+    fk_bookcase_shelf_uid: Mapped[int] = mapped_column(ForeignKey('BookcaseShelf.uid'))
     fk_language_uid: Mapped[int | None] = mapped_column(ForeignKey('Language.uid'))
 
     media_type: Mapped[MediaType] = relationship(back_populates='items')
diff --git a/worblehat/models/migrations/versions/2024-07-28T1412_c3fcf3d979ea_initial_migration.py b/worblehat/models/migrations/versions/2024-07-31T2107_7dfbf8a8dec8_initial_migration.py
similarity index 98%
rename from worblehat/models/migrations/versions/2024-07-28T1412_c3fcf3d979ea_initial_migration.py
rename to worblehat/models/migrations/versions/2024-07-31T2107_7dfbf8a8dec8_initial_migration.py
index 06586ac..faedb69 100644
--- a/worblehat/models/migrations/versions/2024-07-28T1412_c3fcf3d979ea_initial_migration.py
+++ b/worblehat/models/migrations/versions/2024-07-31T2107_7dfbf8a8dec8_initial_migration.py
@@ -1,8 +1,8 @@
 """initial_migration
 
-Revision ID: c3fcf3d979ea
+Revision ID: 7dfbf8a8dec8
 Revises: 
-Create Date: 2024-07-28 14:12:02.772571
+Create Date: 2024-07-31 21:07:13.434012
 
 """
 from alembic import op
@@ -10,7 +10,7 @@ import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
-revision = 'c3fcf3d979ea'
+revision = '7dfbf8a8dec8'
 down_revision = None
 branch_labels = None
 depends_on = None
@@ -85,7 +85,7 @@ def upgrade() -> None:
     sa.Column('owner', sa.String(), nullable=False),
     sa.Column('amount', sa.SmallInteger(), nullable=False),
     sa.Column('fk_media_type_uid', sa.Integer(), nullable=False),
-    sa.Column('fk_bookcase_shelf_uid', sa.Integer(), nullable=True),
+    sa.Column('fk_bookcase_shelf_uid', sa.Integer(), nullable=False),
     sa.Column('fk_language_uid', sa.Integer(), nullable=True),
     sa.Column('uid', sa.Integer(), nullable=False),
     sa.ForeignKeyConstraint(['fk_bookcase_shelf_uid'], ['BookcaseShelf.uid'], name=op.f('fk_BookcaseItem_fk_bookcase_shelf_uid_BookcaseShelf')),