diff --git a/CHANGELOG.md b/CHANGELOG.md
index d2170c400..b28cddbe1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Suggest container query variants ([#15857](https://github.com/tailwindlabs/tailwindcss/pull/15857))
 - Disable bare value suggestions when not using the `--spacing` variable ([#15857](https://github.com/tailwindlabs/tailwindcss/pull/15857))
 - Ensure suggested classes are properly sorted ([#15857](https://github.com/tailwindlabs/tailwindcss/pull/15857))
+- Ensure that `@tailwindcss/browser` does not pollute the global namespace ([#15978](https://github.com/tailwindlabs/tailwindcss/pull/15978))
 - _Upgrade_: Ensure JavaScript config files on different drives are correctly migrated ([#15927](https://github.com/tailwindlabs/tailwindcss/pull/15927))
 
 ## [4.0.0] - 2025-01-21
diff --git a/packages/@tailwindcss-browser/package.json b/packages/@tailwindcss-browser/package.json
index 420c2faf7..aef639cf3 100644
--- a/packages/@tailwindcss-browser/package.json
+++ b/packages/@tailwindcss-browser/package.json
@@ -3,8 +3,8 @@
   "version": "4.0.0",
   "description": "A utility-first CSS framework for rapidly building custom user interfaces.",
   "license": "MIT",
-  "main": "./dist/index.mjs",
-  "browser": "./dist/index.mjs",
+  "main": "./dist/index.global.js",
+  "browser": "./dist/index.global.js",
   "repository": {
     "type": "git",
     "url": "https://github.com/tailwindlabs/tailwindcss.git",
@@ -19,7 +19,7 @@
     "test:ui": "playwright test"
   },
   "exports": {
-    ".": "./dist/index.mjs",
+    ".": "./dist/index.global.js",
     "./package.json": "./package.json"
   },
   "files": [
diff --git a/packages/@tailwindcss-browser/tsup.config.ts b/packages/@tailwindcss-browser/tsup.config.ts
index 57fa6d7dc..5a6d78273 100644
--- a/packages/@tailwindcss-browser/tsup.config.ts
+++ b/packages/@tailwindcss-browser/tsup.config.ts
@@ -1,7 +1,7 @@
 import { defineConfig } from 'tsup'
 
 export default defineConfig({
-  format: ['esm'],
+  format: ['iife'],
   clean: true,
   minify: true,
   entry: ['src/index.ts'],