diff --git a/.changeset/metal-clouds-raise.md b/.changeset/metal-clouds-raise.md
new file mode 100644
index 0000000000..9693100fb3
--- /dev/null
+++ b/.changeset/metal-clouds-raise.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+breaking: move compiler.cjs to compiler/index.js
diff --git a/.eslintignore b/.eslintignore
index fbab8fbc0d..3b486d3f07 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -11,6 +11,7 @@
 **/vite.config.js
 **/vite.prod.config.js
 **/node_modules
+**/compiler/index.js
 
 **/tests/**
 
@@ -20,4 +21,4 @@ documentation/**
 # contains a fork of the REPL which doesn't adhere to eslint rules
 sites/svelte-5-preview/**
 # Wasn't checked previously, reenable at some point
-sites/svelte.dev/** 
+sites/svelte.dev/**
diff --git a/.prettierignore b/.prettierignore
index dc6385309b..558f1fcb85 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -13,7 +13,7 @@ packages/svelte/tests/**/shards/*.test.js
 packages/svelte/tests/hydration/samples/*/_expected.html
 packages/svelte/tests/hydration/samples/*/_override.html
 packages/svelte/types
-packages/svelte/compiler.cjs
+packages/svelte/compiler/index.js
 playgrounds/demo/src
 playgrounds/sandbox/input/**.svelte
 playgrounds/sandbox/output
diff --git a/packages/svelte/.gitignore b/packages/svelte/.gitignore
index 8b3d7652a1..d0c4ba8d61 100644
--- a/packages/svelte/.gitignore
+++ b/packages/svelte/.gitignore
@@ -1,6 +1,6 @@
 /types/*.map
 /types/compiler
-/compiler.cjs
+/compiler/index.js
 
 /action.d.ts
 /animate.d.ts
diff --git a/packages/svelte/compiler/package.json b/packages/svelte/compiler/package.json
new file mode 100644
index 0000000000..5bbefffbab
--- /dev/null
+++ b/packages/svelte/compiler/package.json
@@ -0,0 +1,3 @@
+{
+  "type": "commonjs"
+}
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index e71b7c0c68..09e3a00a71 100644
--- a/packages/svelte/package.json
+++ b/packages/svelte/package.json
@@ -12,7 +12,7 @@
     "src",
     "!src/**/*.test.*",
     "types",
-    "compiler.cjs",
+    "compiler/index.js",
     "*.d.ts",
     "README.md"
   ],
@@ -34,7 +34,7 @@
     },
     "./compiler": {
       "types": "./types/index.d.ts",
-      "require": "./compiler.cjs",
+      "require": "./compiler/index.js",
       "default": "./src/compiler/index.js"
     },
     "./easing": {
diff --git a/packages/svelte/rollup.config.js b/packages/svelte/rollup.config.js
index 5a9a220411..3e36190f9c 100644
--- a/packages/svelte/rollup.config.js
+++ b/packages/svelte/rollup.config.js
@@ -9,7 +9,7 @@ import './scripts/generate-version.js';
 export default defineConfig({
 	input: 'src/compiler/index.js',
 	output: {
-		file: 'compiler.cjs',
+		file: 'compiler/index.js',
 		format: 'umd',
 		name: 'svelte'
 	},
diff --git a/sites/svelte-5-preview/src/lib/workers/bundler/index.js b/sites/svelte-5-preview/src/lib/workers/bundler/index.js
index bd0ee9d67e..80e14badbf 100644
--- a/sites/svelte-5-preview/src/lib/workers/bundler/index.js
+++ b/sites/svelte-5-preview/src/lib/workers/bundler/index.js
@@ -48,10 +48,8 @@ self.addEventListener(
 				const { version } = await fetch(`${svelte_url}/package.json`).then((r) => r.json());
 				console.log(`Using Svelte compiler version ${version}`);
 
-				// unpkg doesn't set the correct MIME type for .cjs files
-				// https://github.com/mjackson/unpkg/issues/355
-				const compiler = await fetch(`${svelte_url}/compiler.cjs`).then((r) => r.text());
-				(0, eval)(compiler + '\n//# sourceURL=compiler.cjs@' + version);
+				const compiler = await fetch(`${svelte_url}/compiler/index.js`).then((r) => r.text());
+				(0, eval)(compiler + '\n//# sourceURL=compiler/index.js@' + version);
 
 				svelte = globalThis.svelte;
 
diff --git a/sites/svelte-5-preview/src/lib/workers/compiler/index.js b/sites/svelte-5-preview/src/lib/workers/compiler/index.js
index d3d7e475d1..d264e702a0 100644
--- a/sites/svelte-5-preview/src/lib/workers/compiler/index.js
+++ b/sites/svelte-5-preview/src/lib/workers/compiler/index.js
@@ -29,10 +29,8 @@ self.addEventListener(
 					.then((r) => r.json())
 					.catch(() => ({ version: 'experimental' }));
 
-				// unpkg doesn't set the correct MIME type for .cjs files
-				// https://github.com/mjackson/unpkg/issues/355
-				const compiler = await fetch(`${svelte_url}/compiler.cjs`).then((r) => r.text());
-				(0, eval)(compiler + '\n//# sourceURL=compiler.cjs@' + version);
+				const compiler = await fetch(`${svelte_url}/compiler/index.js`).then((r) => r.text());
+				(0, eval)(compiler + '\n//# sourceURL=compiler/index.js@' + version);
 
 				svelte = globalThis.svelte;
 
diff --git a/sites/svelte-5-preview/src/routes/svelte/[...path]/+server.js b/sites/svelte-5-preview/src/routes/svelte/[...path]/+server.js
index d2a35f0727..8ac64dd223 100644
--- a/sites/svelte-5-preview/src/routes/svelte/[...path]/+server.js
+++ b/sites/svelte-5-preview/src/routes/svelte/[...path]/+server.js
@@ -1,4 +1,4 @@
-import compiler_cjs from '../../../../../../packages/svelte/compiler.cjs?url';
+import compiler_cjs from '../../../../../../packages/svelte/compiler/index.js?url';
 import package_json from '../../../../../../packages/svelte/package.json?url';
 import { read } from '$app/server';
 
@@ -14,14 +14,14 @@ export const prerender = true;
 
 export function entries() {
 	const entries = Object.keys(files).map((path) => ({ path: path.replace(prefix, '') }));
-	entries.push({ path: 'compiler.cjs' }, { path: 'package.json' });
+	entries.push({ path: 'compiler/index.js' }, { path: 'package.json' });
 	return entries;
 }
 
 // service worker requests files under this path to load the compiler and runtime
 export async function GET({ params }) {
 	let url = '';
-	if (params.path === 'compiler.cjs') {
+	if (params.path === 'compiler/index.js') {
 		url = compiler_cjs;
 	} else if (params.path === 'package.json') {
 		url = package_json;