diff --git a/src/interfaces/bodies/orders/CreateOrderBody.ts b/src/interfaces/bodies/orders/CreateOrderBody.ts
index 3edc652..544de60 100644
--- a/src/interfaces/bodies/orders/CreateOrderBody.ts
+++ b/src/interfaces/bodies/orders/CreateOrderBody.ts
@@ -45,7 +45,7 @@ export const createOrderValidator = [
 		.isString()
 		.matches(NON_NEGATIVE_REAL_NUMBER_REGEX)
 		.withMessage('orderData.amount must be a positive decimal string'),
-	body('orderData.pairId').isString().withMessage('orderData.pairId must be a string'),
+	body('orderData.pairId').isNumeric().withMessage('orderData.pairId must be a number'),
 ];
 
 export default CreateOrderBody;
diff --git a/src/middleware/middleware.ts b/src/middleware/middleware.ts
index 1109da8..35f99ed 100644
--- a/src/middleware/middleware.ts
+++ b/src/middleware/middleware.ts
@@ -60,7 +60,10 @@ class Middleware {
 				if (!errors.isEmpty()) {
 					res.status(500).send({
 						success: false,
-						data: 'Internal error',
+						data: errors
+							.array()
+							.map((err) => err.msg)
+							.join(', '),
 					});
 					return;
 				}