diff --git a/.changeset/friendly-radios-live.md b/.changeset/friendly-radios-live.md
new file mode 100644
index 0000000000..723a3d7f83
--- /dev/null
+++ b/.changeset/friendly-radios-live.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Reverts a change made in `4.16.6` that prevented usage of `astro:env` secrets inside middleware in SSR
diff --git a/packages/astro/src/env/runtime-constants.ts b/packages/astro/src/env/runtime-constants.ts
deleted file mode 100644
index 27b5d72113..0000000000
--- a/packages/astro/src/env/runtime-constants.ts
+++ /dev/null
@@ -1 +0,0 @@
-export const ENV_SYMBOL = Symbol.for('astro:env/dev');
diff --git a/packages/astro/src/env/runtime.ts b/packages/astro/src/env/runtime.ts
index 50684f63ef..a2017b617f 100644
--- a/packages/astro/src/env/runtime.ts
+++ b/packages/astro/src/env/runtime.ts
@@ -1,16 +1,12 @@
 import { AstroError, AstroErrorData } from '../core/errors/index.js';
 import { invalidVariablesToError } from './errors.js';
-import { ENV_SYMBOL } from './runtime-constants.js';
 import type { ValidationResultInvalid } from './validators.js';
 export { validateEnvVariable, getEnvFieldType } from './validators.js';
 
 export type GetEnv = (key: string) => string | undefined;
 type OnSetGetEnv = (reset: boolean) => void;
 
-let _getEnv: GetEnv = (key) => {
-	const env = (globalThis as any)[ENV_SYMBOL] ?? {};
-	return env[key];
-};
+let _getEnv: GetEnv = (key) => process.env[key];
 
 export function setGetEnv(fn: GetEnv, reset = false) {
 	_getEnv = fn;
diff --git a/packages/astro/src/env/vite-plugin-env.ts b/packages/astro/src/env/vite-plugin-env.ts
index a672addccd..06d5b047c9 100644
--- a/packages/astro/src/env/vite-plugin-env.ts
+++ b/packages/astro/src/env/vite-plugin-env.ts
@@ -9,7 +9,6 @@ import {
 	VIRTUAL_MODULES_IDS_VALUES,
 } from './constants.js';
 import { type InvalidVariable, invalidVariablesToError } from './errors.js';
-import { ENV_SYMBOL } from './runtime-constants.js';
 import type { EnvSchema } from './schema.js';
 import { getEnvFieldType, validateEnvVariable } from './validators.js';
 
@@ -42,7 +41,11 @@ export function astroEnv({
 				fileURLToPath(settings.config.root),
 				'',
 			);
-			(globalThis as any)[ENV_SYMBOL] = loadedEnv;
+			for (const [key, value] of Object.entries(loadedEnv)) {
+				if (value !== undefined) {
+					process.env[key] = value;
+				}
+			}
 
 			const validatedVariables = validatePublicVariables({
 				schema,