diff --git a/includes/api/class-wc-rest-order-notes-controller.php b/includes/api/class-wc-rest-order-notes-controller.php
index 3b1ea077ad0..242dada4125 100644
--- a/includes/api/class-wc-rest-order-notes-controller.php
+++ b/includes/api/class-wc-rest-order-notes-controller.php
@@ -310,7 +310,7 @@ class WC_REST_Order_Notes_Controller extends WC_REST_Controller {
 	 */
 	public function prepare_item_for_response( $note, $request ) {
 		$data = array(
-			'id'            => $note->comment_ID,
+			'id'            => (int) $note->comment_ID,
 			'date_created'  => wc_rest_prepare_date_response( $note->comment_date_gmt ),
 			'note'          => $note->comment_content,
 			'customer_note' => (bool) get_comment_meta( $note->comment_ID, 'is_customer_note', true ),