diff --git a/includes/api/class-wc-rest-orders-controller.php b/includes/api/class-wc-rest-orders-controller.php
index 5350bf42628..b42e8c97e9c 100644
--- a/includes/api/class-wc-rest-orders-controller.php
+++ b/includes/api/class-wc-rest-orders-controller.php
@@ -597,8 +597,9 @@ class WC_REST_Orders_Controller extends WC_REST_Legacy_Orders_Controller {
 	protected function maybe_set_item_meta_data( $item, $posted ) {
 		if ( ! empty( $posted['meta_data'] ) && is_array( $posted['meta_data'] ) ) {
 			foreach ( $posted['meta_data'] as $meta ) {
-				if ( isset( $meta['key'], $meta['value'] ) ) {
-					$item->update_meta_data( $meta['key'], $meta['value'], isset( $meta['id'] ) ? $meta['id'] : '' );
+				if ( isset( $meta['key'] ) ) {
+					$value = isset( $meta['value'] ) ? $meta['value'] : null;
+					$item->update_meta_data( $meta['key'], $value, isset( $meta['id'] ) ? $meta['id'] : '' );
 				}
 			}
 		}