diff --git a/models/App.js b/models/App.js
index 03f5dc5..fa9c6c4 100644
--- a/models/App.js
+++ b/models/App.js
@@ -12,7 +12,8 @@ const App = sequelize.define('App', {
   },
   categoryId: {
     type: DataTypes.INTEGER,
-    allowNull: false
+    allowNull: false,
+    defaultValue: -1  // Default value for database migration only
   },
   icon: {
     type: DataTypes.STRING,
diff --git a/models/Category.js b/models/Category.js
index 75bda95..4256d21 100644
--- a/models/Category.js
+++ b/models/Category.js
@@ -8,7 +8,8 @@ const Category = sequelize.define('Category', {
   },
   type: {
     type: DataTypes.STRING,
-    allowNull: false
+    allowNull: false,
+    defaultValue: 'bookmark' // Default value for database migration only
   },
   isPinned: {
     type: DataTypes.BOOLEAN,