diff --git a/packages/svelte/src/compiler/migrate/index.js b/packages/svelte/src/compiler/migrate/index.js
index 0370155c12..10a0274b30 100644
--- a/packages/svelte/src/compiler/migrate/index.js
+++ b/packages/svelte/src/compiler/migrate/index.js
@@ -149,7 +149,8 @@ export function migrate(source, { filename, use_ts } = {}) {
 			css: 'css' in parsed_options ? () => parsed_options.css ?? 'external' : () => 'external',
 			runes: 'runes' in parsed_options ? () => parsed_options.runes : () => undefined,
 			experimental: {
-				async: true
+				async: true,
+				customRenderer: () => undefined
 			}
 		};