diff --git a/src/database/constants.ts b/src/database/constants.ts
index e5d9b315..d44ef0c5 100644
--- a/src/database/constants.ts
+++ b/src/database/constants.ts
@@ -28,3 +28,8 @@ export const CHAPTER_FILTER = {
 export type ChapterFilterPositiveKey = keyof typeof CHAPTER_FILTER_POSITIVE;
 export type ChapterFilterKey = keyof typeof CHAPTER_FILTER;
 export type ChapterFilter = (typeof CHAPTER_FILTER)[ChapterFilterKey];
+
+export const BUILT_IN_CATEGORY_IDS = {
+  default: 1,
+  local: 2,
+} as const;
diff --git a/src/database/queries/CategoryQueries.ts b/src/database/queries/CategoryQueries.ts
index c802cedf..fd97998a 100644
--- a/src/database/queries/CategoryQueries.ts
+++ b/src/database/queries/CategoryQueries.ts
@@ -186,10 +186,10 @@ export const updateCategoryOrderInDb = async (
   }
 
   await dbManager.write(async tx => {
-    for (const category of categories) {
+    for (const [index, category] of categories.entries()) {
       await tx
         .update(categorySchema)
-        .set({ sort: category.sort })
+        .set({ sort: index + 1 })
         .where(eq(categorySchema.id, category.id))
         .run();
     }
diff --git a/src/database/queries/NovelQueries.ts b/src/database/queries/NovelQueries.ts
index 00d9a5f4..91681dc0 100644
--- a/src/database/queries/NovelQueries.ts
+++ b/src/database/queries/NovelQueries.ts
@@ -21,6 +21,7 @@ import {
 import type { TransactionParameter } from '@database/manager/manager.d';
 import { getLibraryDefaultCategoryId } from '@hooks/persisted/useSettings';
 import NativeFile from '@modules/native-file';
+import { BUILT_IN_CATEGORY_IDS } from '@database/constants';
 
 const getCategoryForNewNovel = async (tx: TransactionParameter) => {
   const preferredCategoryId = getLibraryDefaultCategoryId();
@@ -40,7 +41,7 @@ const getCategoryForNewNovel = async (tx: TransactionParameter) => {
   return tx
     .select({ id: categorySchema.id })
     .from(categorySchema)
-    .where(eq(categorySchema.sort, 1))
+    .where(eq(categorySchema.id, BUILT_IN_CATEGORY_IDS.default))
     .get();
 };
 
@@ -174,7 +175,7 @@ export const switchNovelToLibraryQuery = async (
             .insert(novelCategorySchema)
             .values({
               novelId: novel.id,
-              categoryId: 2,
+              categoryId: BUILT_IN_CATEGORY_IDS.local,
             })
             .onConflictDoNothing()
             .run();
@@ -386,7 +387,7 @@ export const updateNovelCategories = async (
       .where(
         and(
           inArray(novelCategorySchema.novelId, novelIds),
-          ne(novelCategorySchema.categoryId, 2),
+          ne(novelCategorySchema.categoryId, BUILT_IN_CATEGORY_IDS.local),
         ),
       )
       .run();
diff --git a/src/database/queries/__tests__/CategoryQueries.test.ts b/src/database/queries/__tests__/CategoryQueries.test.ts
index 5e49d6e0..1a13ae9c 100644
--- a/src/database/queries/__tests__/CategoryQueries.test.ts
+++ b/src/database/queries/__tests__/CategoryQueries.test.ts
@@ -212,7 +212,7 @@ describe('CategoryQueries', () => {
   });
 
   describe('updateCategoryOrderInDb', () => {
-    it('should update sort order for multiple categories', async () => {
+    it('should persist categories using one-based display order', async () => {
       const testDb = getTestDb();
       const cat1 = await insertTestCategory(testDb, {
         name: 'Cat 1',
@@ -231,8 +231,8 @@ describe('CategoryQueries', () => {
       const categories = await getCategoriesFromDb();
       const updated1 = categories.find(c => c.id === cat1);
       const updated2 = categories.find(c => c.id === cat2);
-      expect(updated1?.sort).toBe(30);
-      expect(updated2?.sort).toBe(40);
+      expect(updated1?.sort).toBe(1);
+      expect(updated2?.sort).toBe(2);
     });
 
     it('should handle empty array', async () => {
diff --git a/src/database/queries/__tests__/NovelQueries.test.ts b/src/database/queries/__tests__/NovelQueries.test.ts
index 3aaba46f..5bd3b41f 100644
--- a/src/database/queries/__tests__/NovelQueries.test.ts
+++ b/src/database/queries/__tests__/NovelQueries.test.ts
@@ -13,7 +13,8 @@ import {
   clearAllTables,
 } from './testData';
 import { categorySchema, novelCategorySchema } from '@database/schema';
-import { eq, sql } from 'drizzle-orm';
+import { eq } from 'drizzle-orm';
+import { BUILT_IN_CATEGORY_IDS } from '@database/constants';
 
 import {
   getAllNovels,
@@ -178,7 +179,7 @@ describe('NovelQueries', () => {
       expect(Boolean(novel?.inLibrary)).toBe(false);
     });
 
-    it('should assign default category when adding to library', async () => {
+    it('should fall back to the built-in default category by ID', async () => {
       const testDb = getTestDb();
       const novelId = await insertTestNovel(testDb, {
         inLibrary: false,
@@ -186,12 +187,16 @@ describe('NovelQueries', () => {
         pluginId: 'test-plugin',
       });
 
-      // Get default category (sort = 1)
-      const defaultCategory = await testDb.drizzleDb
-        .select()
-        .from(categorySchema)
-        .where(sql`${categorySchema.sort} = 1`)
-        .get();
+      await testDb.drizzleDb
+        .update(categorySchema)
+        .set({ sort: 0 })
+        .where(eq(categorySchema.id, BUILT_IN_CATEGORY_IDS.default))
+        .run();
+      await testDb.drizzleDb
+        .update(categorySchema)
+        .set({ sort: 1 })
+        .where(eq(categorySchema.id, BUILT_IN_CATEGORY_IDS.local))
+        .run();
 
       await switchNovelToLibraryQuery('/test/novel', 'test-plugin');
 
@@ -202,10 +207,17 @@ describe('NovelQueries', () => {
         .all();
 
       expect(associations.length).toBeGreaterThan(0);
-
       expect(
-        associations.some(a => a.categoryId === (defaultCategory?.id ?? -1)),
-      ).toBe(!!defaultCategory);
+        associations.some(
+          association =>
+            association.categoryId === BUILT_IN_CATEGORY_IDS.default,
+        ),
+      ).toBe(true);
+      expect(
+        associations.some(
+          association => association.categoryId === BUILT_IN_CATEGORY_IDS.local,
+        ),
+      ).toBe(false);
     });
 
     it('should assign the user-selected default category', async () => {
@@ -257,7 +269,10 @@ describe('NovelQueries', () => {
         .all();
 
       expect(
-        associations.some(association => association.categoryId === 1),
+        associations.some(
+          association =>
+            association.categoryId === BUILT_IN_CATEGORY_IDS.default,
+        ),
       ).toBe(true);
     });
   });
diff --git a/src/screens/Categories/CategoriesScreen.tsx b/src/screens/Categories/CategoriesScreen.tsx
index ea45ab5f..2561c575 100644
--- a/src/screens/Categories/CategoriesScreen.tsx
+++ b/src/screens/Categories/CategoriesScreen.tsx
@@ -51,13 +51,8 @@ const CategoriesScreen = () => {
       return;
     }
 
-    const updatedOrderCategories = data.map((category, index) => ({
-      ...category,
-      sort: index,
-    }));
-
-    setCategories(updatedOrderCategories);
-    updateCategoryOrderInDb(updatedOrderCategories);
+    setCategories(data);
+    updateCategoryOrderInDb(data);
   };
 
   const renderItem = ({