diff --git a/Backend/src/validators/CoursesInstructor.validator.ts b/Backend/src/validators/CoursesInstructor.validator.ts
index 08ab90b5..fe971950 100644
--- a/Backend/src/validators/CoursesInstructor.validator.ts
+++ b/Backend/src/validators/CoursesInstructor.validator.ts
@@ -16,7 +16,6 @@ export const CreateCourseValidator = Joi.object({
         th: Joi.string().required(),
         en: Joi.string().required(),
     }).required(),
-    thumbnail_url: Joi.string().required(),
     price: Joi.number().required(),
     is_free: Joi.boolean().required(),
     have_certificate: Joi.boolean().required(),