diff --git a/app/views/book.py b/app/views/book.py
index 67b0e51..3dcdace 100644
--- a/app/views/book.py
+++ b/app/views/book.py
@@ -377,8 +377,16 @@ def collection_create(book_id: int, collection_id: int | None = None):
     if form.validate_on_submit():
         label = form.label.data
         collection: m.Collection = m.Collection.query.filter_by(
-            is_deleted=False, label=label, version_id=book.versions[-1].id
-        ).first()
+            is_deleted=False,
+            label=label,
+        )
+        if collection_id:
+            collection = collection.filter_by(parrent_id=collection_id)
+        else:
+            collection = collection.filter_by(
+                parrent_id=book.versions[-1].root_collection.id
+            )
+        collection = collection.first()
 
         if collection:
             log(
@@ -461,12 +469,19 @@ def collection_edit(
 
     if form.validate_on_submit():
         label = form.label.data
+        collection_query: m.Collection = m.Collection.query.filter_by(
+            is_deleted=False,
+            label=label,
+        ).filter(m.Collection.id != collection_to_edit.id)
 
-        if (
-            m.Collection.query.filter_by(label=label, version_id=book.versions[-1].id)
-            .filter(m.Collection.id != collection_to_edit.id)
-            .first()
-        ):
+        if sub_collection_id:
+            collection_query = collection_query.filter_by(parrent_id=collection_id)
+        else:
+            collection_query = collection_query.filter_by(
+                parrent_id=collection_to_edit.parrent.id
+            )
+
+        if collection_query.first():
             log(
                 log.INFO,
                 "Collection with similar label already exists. Book: [%s], Collection: [%s], Label: [%s]",
diff --git a/tests/test_book.py b/tests/test_book.py
index aee9925..13bfb39 100644
--- a/tests/test_book.py
+++ b/tests/test_book.py
@@ -219,7 +219,9 @@ def test_crud_collection(client: FlaskClient, runner: FlaskCliRunner):
         label="Test Collection #1 Label"
     ).first()
     m.Collection(
-        label="Test Collection #2 Label", version_id=collection.version_id
+        label="Test Collection #2 Label",
+        version_id=collection.version_id,
+        parrent_id=collection.parrent_id,
     ).save()
 
     response: Response = client.post(
@@ -300,6 +302,7 @@ def test_crud_subcollection(client: FlaskClient, runner: FlaskCliRunner):
         label="Test Leaf Collection #1 Label",
         version_id=book.versions[-1].id,
         is_leaf=True,
+        parrent_id=book.versions[-1].root_collection.id,
     ).save()
     collection: m.Collection = m.Collection(
         label="Test Collection #1 Label", version_id=book.versions[-1].id
@@ -329,7 +332,9 @@ def test_crud_subcollection(client: FlaskClient, runner: FlaskCliRunner):
 
     response: Response = client.post(
         f"/book/{book.id}/{collection.id}/create_sub_collection",
-        data=dict(label="Test Collection #1 Label", about="Test Collection #1 About"),
+        data=dict(
+            label="Test SubCollection #1 Label", about="Test SubCollection #1 About"
+        ),
         follow_redirects=True,
     )
 
@@ -400,7 +405,7 @@ def test_crud_subcollection(client: FlaskClient, runner: FlaskCliRunner):
     assert response.status_code == 200
     assert b"Success!" in response.data
 
-    deleted_collection: m.Collection = db.session.get(m.Collection, collection.id)
+    deleted_collection: m.Collection = db.session.get(m.Collection, sub_collection.id)
     assert deleted_collection.is_deleted
 
     response: Response = client.post(