diff --git a/.changeset/brown-impalas-travel.md b/.changeset/brown-impalas-travel.md
new file mode 100644
index 000000000000..3947a3fa2635
--- /dev/null
+++ b/.changeset/brown-impalas-travel.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Include service worker in manifest
diff --git a/packages/kit/src/core/build/index.js b/packages/kit/src/core/build/index.js
index 0c6751ae0712..df8f43ca14fb 100644
--- a/packages/kit/src/core/build/index.js
+++ b/packages/kit/src/core/build/index.js
@@ -57,6 +57,7 @@ export async function build(config) {
 	const build_data = {
 		app_dir: config.kit.appDir,
 		manifest_data: options.manifest_data,
+		service_worker: options.service_worker_entry_file ? 'service_worker.js' : null, // TODO make file configurable?
 		client,
 		server,
 		static: options.manifest_data.assets.map((asset) => posixify(asset.file)),
diff --git a/packages/kit/src/core/generate_manifest/index.js b/packages/kit/src/core/generate_manifest/index.js
index a2cb05d6e9d6..c98b8f8065a3 100644
--- a/packages/kit/src/core/generate_manifest/index.js
+++ b/packages/kit/src/core/generate_manifest/index.js
@@ -47,10 +47,15 @@ export function generate_manifest(
 			? (path) => `() => import('${path}')`
 			: (path) => `() => Promise.resolve().then(() => require('${path}'))`;
 
+	const assets = build_data.manifest_data.assets.map((asset) => asset.file);
+	if (build_data.service_worker) {
+		assets.push(build_data.service_worker);
+	}
+
 	// prettier-ignore
 	return `{
 		appDir: ${s(build_data.app_dir)},
-		assets: new Set(${s(build_data.manifest_data.assets.map(asset => asset.file))}),
+		assets: new Set(${s(assets)}),
 		_: {
 			mime: ${s(get_mime_lookup(build_data.manifest_data))},
 			entry: ${s(build_data.client.entry)},
diff --git a/packages/kit/types/internal.d.ts b/packages/kit/types/internal.d.ts
index 8fa01b89a964..294ed943db1d 100644
--- a/packages/kit/types/internal.d.ts
+++ b/packages/kit/types/internal.d.ts
@@ -209,6 +209,7 @@ export interface ManifestData {
 export interface BuildData {
 	app_dir: string;
 	manifest_data: ManifestData;
+	service_worker: string | null;
 	client: {
 		assets: OutputAsset[];
 		chunks: OutputChunk[];