diff --git a/models/category.ts b/models/category.ts
index fb0d044..964aca6 100644
--- a/models/category.ts
+++ b/models/category.ts
@@ -9,4 +9,8 @@ export interface Category { //_id is not needed as it is created by default
 
 export interface MongoCategory extends Omit<Category, 'shelves'> {
     shelves?: Array<string>, // Shelf IDs
+}
+
+export interface MobileCategory extends MongoCategory {
+    _id: string,
 }
\ No newline at end of file