diff --git a/.changeset/sixty-trainers-shout.md b/.changeset/sixty-trainers-shout.md
new file mode 100644
index 000000000..8838fdede
--- /dev/null
+++ b/.changeset/sixty-trainers-shout.md
@@ -0,0 +1,7 @@
+---
+'@astrojs/netlify': minor
+'@astrojs/vercel': minor
+'@astrojs/node': minor
+---
+
+Cleans up `astro:env` support
diff --git a/packages/netlify/src/index.ts b/packages/netlify/src/index.ts
index 11dfafe51..c48b952af 100644
--- a/packages/netlify/src/index.ts
+++ b/packages/netlify/src/index.ts
@@ -141,16 +141,6 @@ async function writeNetlifyFrameworkConfig(config: AstroConfig, logger: AstroInt
 	);
 }
 
-// TODO: remove once we don't use a TLA anymore
-async function shouldExternalizeAstroEnvSetup() {
-	try {
-		await import('astro/env/setup');
-		return false;
-	} catch {
-		return true;
-	}
-}
-
 export interface NetlifyIntegrationConfig {
 	/**
 	 * If enabled, On-Demand-Rendered pages are cached for up to a year.
@@ -435,11 +425,6 @@ export default function netlifyIntegration(
 								ignored: [fileURLToPath(new URL('./.netlify/**', rootDir))],
 							},
 						},
-						...((await shouldExternalizeAstroEnvSetup())
-							? {
-									ssr: { external: ['astro/env/setup'] },
-								}
-							: {}),
 					},
 					image: {
 						service: {
diff --git a/packages/netlify/src/polyfill.ts b/packages/netlify/src/polyfill.ts
new file mode 100644
index 000000000..dc00f45d7
--- /dev/null
+++ b/packages/netlify/src/polyfill.ts
@@ -0,0 +1,3 @@
+import { applyPolyfills } from 'astro/app/node';
+
+applyPolyfills();
diff --git a/packages/netlify/src/ssr-function.ts b/packages/netlify/src/ssr-function.ts
index 22925ddaa..5ea2e97f1 100644
--- a/packages/netlify/src/ssr-function.ts
+++ b/packages/netlify/src/ssr-function.ts
@@ -1,15 +1,12 @@
+// Keep at the top
+import './polyfill.js';
+
 import type { Context } from '@netlify/functions';
 import type { SSRManifest } from 'astro';
 import { App } from 'astro/app';
-import { applyPolyfills } from 'astro/app/node';
-
-applyPolyfills();
+import { setGetEnv } from 'astro/env/setup';
 
-// Won't throw if the virtual module is not available because it's not supported in
-// the users's astro version or if astro:env is not enabled in the project
-await import('astro/env/setup')
-	.then((mod) => mod.setGetEnv((key) => process.env[key]))
-	.catch(() => {});
+setGetEnv((key) => process.env[key]);
 
 export interface Args {
 	middlewareSecret: string;
diff --git a/packages/node/src/index.ts b/packages/node/src/index.ts
index dbd39e6ea..999033a97 100644
--- a/packages/node/src/index.ts
+++ b/packages/node/src/index.ts
@@ -27,16 +27,6 @@ export function getAdapter(options: Options): AstroAdapter {
 	};
 }
 
-// TODO: remove once we don't use a TLA anymore
-async function shouldExternalizeAstroEnvSetup() {
-	try {
-		await import('astro/env/setup');
-		return false;
-	} catch {
-		return true;
-	}
-}
-
 export default function createIntegration(userOptions: UserOptions): AstroIntegration {
 	if (!userOptions?.mode) {
 		throw new AstroError(`Setting the 'mode' option is required.`);
@@ -54,11 +44,6 @@ export default function createIntegration(userOptions: UserOptions): AstroIntegr
 					vite: {
 						ssr: {
 							noExternal: ['@astrojs/node'],
-							...((await shouldExternalizeAstroEnvSetup())
-								? {
-										external: ['astro/env/setup'],
-									}
-								: {}),
 						},
 					},
 				});
diff --git a/packages/node/src/polyfill.ts b/packages/node/src/polyfill.ts
new file mode 100644
index 000000000..dc00f45d7
--- /dev/null
+++ b/packages/node/src/polyfill.ts
@@ -0,0 +1,3 @@
+import { applyPolyfills } from 'astro/app/node';
+
+applyPolyfills();
diff --git a/packages/node/src/server.ts b/packages/node/src/server.ts
index 93d75d360..cef262b47 100644
--- a/packages/node/src/server.ts
+++ b/packages/node/src/server.ts
@@ -1,13 +1,14 @@
+// Keep at the top
+import './polyfill.js';
+
 import type { SSRManifest } from 'astro';
-import { NodeApp, applyPolyfills } from 'astro/app/node';
+import { NodeApp } from 'astro/app/node';
 import { setGetEnv } from 'astro/env/setup';
 import createMiddleware from './middleware.js';
 import { createStandaloneHandler } from './standalone.js';
 import startServer from './standalone.js';
 import type { Options } from './types.js';
 
-// This needs to run first because some internals depend on `crypto`
-applyPolyfills();
 setGetEnv((key) => process.env[key]);
 
 export function createExports(manifest: SSRManifest, options: Options) {
diff --git a/packages/vercel/src/serverless/adapter.ts b/packages/vercel/src/serverless/adapter.ts
index b8cf1f2bc..df4a02357 100644
--- a/packages/vercel/src/serverless/adapter.ts
+++ b/packages/vercel/src/serverless/adapter.ts
@@ -260,10 +260,7 @@ export default function vercelServerless({
 					vite: {
 						...getSpeedInsightsViteConfig(speedInsights?.enabled),
 						ssr: {
-							external: [
-								'@vercel/nft',
-								...((await shouldExternalizeAstroEnvSetup()) ? ['astro/env/setup'] : []),
-							],
+							external: ['@vercel/nft'],
 						},
 					},
 					...getAstroImageConfig(
@@ -426,16 +423,6 @@ export default function vercelServerless({
 
 type Runtime = `nodejs${string}.x`;
 
-// TODO: remove once we don't use a TLA anymore
-async function shouldExternalizeAstroEnvSetup() {
-	try {
-		await import('astro/env/setup');
-		return false;
-	} catch {
-		return true;
-	}
-}
-
 class VercelBuilder {
 	readonly NTF_CACHE = {};
 
diff --git a/packages/vercel/src/serverless/entrypoint.ts b/packages/vercel/src/serverless/entrypoint.ts
index e2c146ed8..01279a2b4 100644
--- a/packages/vercel/src/serverless/entrypoint.ts
+++ b/packages/vercel/src/serverless/entrypoint.ts
@@ -1,6 +1,9 @@
+// Keep at the top
+import './polyfill.js';
+
 import type { IncomingMessage, ServerResponse } from 'node:http';
 import type { SSRManifest } from 'astro';
-import { NodeApp, applyPolyfills } from 'astro/app/node';
+import { NodeApp } from 'astro/app/node';
 import { setGetEnv } from 'astro/env/setup';
 import {
 	ASTRO_LOCALS_HEADER,
@@ -9,8 +12,6 @@ import {
 	ASTRO_PATH_PARAM,
 } from './adapter.js';
 
-// Run polyfills immediately so any dependent code can use the globals
-applyPolyfills();
 setGetEnv((key) => process.env[key]);
 
 export const createExports = (
diff --git a/packages/vercel/src/serverless/polyfill.ts b/packages/vercel/src/serverless/polyfill.ts
new file mode 100644
index 000000000..dc00f45d7
--- /dev/null
+++ b/packages/vercel/src/serverless/polyfill.ts
@@ -0,0 +1,3 @@
+import { applyPolyfills } from 'astro/app/node';
+
+applyPolyfills();