Index: src/wp-includes/rest-api/class-wp-rest-server.php
===================================================================
--- src/wp-includes/rest-api/class-wp-rest-server.php	(revision 40429)
+++ src/wp-includes/rest-api/class-wp-rest-server.php	(working copy)
@@ -251,9 +251,7 @@
 		 */
 		$send_no_cache_headers = apply_filters( 'rest_send_nocache_headers', is_user_logged_in() );
 		if ( $send_no_cache_headers ) {
-			foreach ( wp_get_nocache_headers() as $header => $header_value ) {
-				$this->send_header( $header, $header_value );
-			}
+			nocache_headers();
 		}
 
 		/**