diff --git a/.changeset/chilly-jokes-fold.md b/.changeset/chilly-jokes-fold.md
new file mode 100644
index 0000000000..3410cdeb95
--- /dev/null
+++ b/.changeset/chilly-jokes-fold.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes a case where invalid `astro:env` variables at runtime would not throw correctly
diff --git a/packages/astro/dev-only.d.ts b/packages/astro/dev-only.d.ts
new file mode 100644
index 0000000000..5a5420a95c
--- /dev/null
+++ b/packages/astro/dev-only.d.ts
@@ -0,0 +1,5 @@
+// IMPORTANT: do not publish this file! It's only intended for development within the monorepo
+
+declare module 'virtual:astro:env/internal' {
+	export const schema: import('./src/env/schema.js').EnvSchema;
+}
diff --git a/packages/astro/src/core/errors/errors-data.ts b/packages/astro/src/core/errors/errors-data.ts
index 886fd296e4..8b586e6d2c 100644
--- a/packages/astro/src/core/errors/errors-data.ts
+++ b/packages/astro/src/core/errors/errors-data.ts
@@ -1235,6 +1235,8 @@ export const RouteNotFound = {
  * @docs
  * @description
  * Some environment variables do not match the data type and/or properties defined in `experimental.env.schema`.
+ * @message
+ * The following environment variables defined in `experimental.env.schema` are invalid.
  */
 export const EnvInvalidVariables = {
 	name: 'EnvInvalidVariables',
@@ -1243,18 +1245,6 @@ export const EnvInvalidVariables = {
 		`The following environment variables defined in \`experimental.env.schema\` are invalid:\n\n${errors.map((err) => `- ${err}`).join('\n')}\n`,
 } satisfies ErrorData;
 
-/**
- * @docs
- * @description
- * An environment variable does not match the data type and/or properties defined in `experimental.env.schema`.
- */
-export const EnvInvalidVariable = {
-	name: 'EnvInvalidVariable',
-	title: 'Invalid Environment Variable',
-	message: (key: string, type: string) =>
-		`The following environment variable does not match the data type and/or properties defined in \`experimental.env.schema\`: ${key} is not of type ${type}`,
-} satisfies ErrorData;
-
 /**
  * @docs
  * @description
diff --git a/packages/astro/src/env/errors.ts b/packages/astro/src/env/errors.ts
new file mode 100644
index 0000000000..6fcbd5b3dd
--- /dev/null
+++ b/packages/astro/src/env/errors.ts
@@ -0,0 +1,22 @@
+import type { ValidationResultErrors } from './validators.js';
+
+export interface InvalidVariable {
+	key: string;
+	type: string;
+	errors: ValidationResultErrors;
+}
+
+export function invalidVariablesToError(invalid: Array<InvalidVariable>) {
+	const _errors: Array<string> = [];
+	for (const { key, type, errors } of invalid) {
+		if (errors[0] === 'missing') {
+			_errors.push(`${key} is missing`);
+		} else if (errors[0] === 'type') {
+			_errors.push(`${key}'s type is invalid, expected: ${type}`);
+		} else {
+			// constraints
+			_errors.push(`The following constraints for ${key} are not met: ${errors.join(', ')}`);
+		}
+	}
+	return _errors;
+}
diff --git a/packages/astro/src/env/runtime.ts b/packages/astro/src/env/runtime.ts
index 317e9110fe..57729cdb8b 100644
--- a/packages/astro/src/env/runtime.ts
+++ b/packages/astro/src/env/runtime.ts
@@ -1,5 +1,7 @@
 import { AstroError, AstroErrorData } from '../core/errors/index.js';
-export { validateEnvVariable } from './validators.js';
+import { invalidVariablesToError } from './errors.js';
+import type { ValidationResultInvalid } from './validators.js';
+export { validateEnvVariable, getEnvFieldType } from './validators.js';
 
 export type GetEnv = (key: string) => string | undefined;
 
@@ -21,11 +23,15 @@ export function getEnv(...args: Parameters<GetEnv>) {
 	return _getEnv(...args);
 }
 
-export function createInvalidVariableError(
-	...args: Parameters<typeof AstroErrorData.EnvInvalidVariable.message>
+export function createInvalidVariablesError(
+	key: string,
+	type: string,
+	result: ValidationResultInvalid
 ) {
 	return new AstroError({
-		...AstroErrorData.EnvInvalidVariable,
-		message: AstroErrorData.EnvInvalidVariable.message(...args),
+		...AstroErrorData.EnvInvalidVariables,
+		message: AstroErrorData.EnvInvalidVariables.message(
+			invalidVariablesToError([{ key, type, errors: result.errors }])
+		),
 	});
 }
diff --git a/packages/astro/src/env/validators.ts b/packages/astro/src/env/validators.ts
index 4e5d342875..8776793cb0 100644
--- a/packages/astro/src/env/validators.ts
+++ b/packages/astro/src/env/validators.ts
@@ -2,16 +2,15 @@ import type { EnumSchema, EnvFieldType, NumberSchema, StringSchema } from './sch
 
 export type ValidationResultValue = EnvFieldType['default'];
 export type ValidationResultErrors = ['missing'] | ['type'] | Array<string>;
-
-type ValidationResult =
-	| {
-			ok: true;
-			value: ValidationResultValue;
-	  }
-	| {
-			ok: false;
-			errors: ValidationResultErrors;
-	  };
+interface ValidationResultValid {
+	ok: true;
+	value: ValidationResultValue;
+}
+export interface ValidationResultInvalid {
+	ok: false;
+	errors: ValidationResultErrors;
+}
+type ValidationResult = ValidationResultValid | ValidationResultInvalid;
 
 export function getEnvFieldType(options: EnvFieldType) {
 	const optional = options.optional ? (options.default !== undefined ? false : true) : false;
diff --git a/packages/astro/src/env/vite-plugin-env.ts b/packages/astro/src/env/vite-plugin-env.ts
index 3f1ca2b6bd..a922a92123 100644
--- a/packages/astro/src/env/vite-plugin-env.ts
+++ b/packages/astro/src/env/vite-plugin-env.ts
@@ -9,7 +9,8 @@ import {
 	VIRTUAL_MODULES_IDS_VALUES,
 } from './constants.js';
 import type { EnvSchema } from './schema.js';
-import { type ValidationResultErrors, getEnvFieldType, validateEnvVariable } from './validators.js';
+import { getEnvFieldType, validateEnvVariable } from './validators.js';
+import { invalidVariablesToError, type InvalidVariable } from './errors.js';
 
 // TODO: reminders for when astro:env comes out of experimental
 // Types should always be generated (like in types/content.d.ts). That means the client module will be empty
@@ -105,7 +106,7 @@ function validatePublicVariables({
 	validateSecrets: boolean;
 }) {
 	const valid: Array<{ key: string; value: any; type: string; context: 'server' | 'client' }> = [];
-	const invalid: Array<{ key: string; type: string; errors: ValidationResultErrors }> = [];
+	const invalid: Array<InvalidVariable> = [];
 
 	for (const [key, options] of Object.entries(schema)) {
 		const variable = loadedEnv[key] === '' ? undefined : loadedEnv[key];
@@ -125,20 +126,9 @@ function validatePublicVariables({
 	}
 
 	if (invalid.length > 0) {
-		const _errors: Array<string> = [];
-		for (const { key, type, errors } of invalid) {
-			if (errors[0] === 'missing') {
-				_errors.push(`${key} is missing`);
-			} else if (errors[0] === 'type') {
-				_errors.push(`${key}'s type is invalid, expected: ${type}`);
-			} else {
-				// constraints
-				_errors.push(`The following constraints for ${key} are not met: ${errors.join(', ')}`);
-			}
-		}
 		throw new AstroError({
 			...AstroErrorData.EnvInvalidVariables,
-			message: AstroErrorData.EnvInvalidVariables.message(_errors),
+			message: AstroErrorData.EnvInvalidVariables.message(invalidVariablesToError(invalid)),
 		});
 	}
 
diff --git a/packages/astro/templates/env/module.mjs b/packages/astro/templates/env/module.mjs
index 952dadbba1..08c0a0a7a5 100644
--- a/packages/astro/templates/env/module.mjs
+++ b/packages/astro/templates/env/module.mjs
@@ -1,9 +1,11 @@
+// @ts-check
 import { schema } from 'virtual:astro:env/internal';
 import {
-	createInvalidVariableError,
+	createInvalidVariablesError,
 	getEnv,
 	setOnSetGetEnv,
 	validateEnvVariable,
+	getEnvFieldType,
 } from 'astro/env/runtime';
 
 export const getSecret = (key) => {
@@ -19,7 +21,8 @@ const _internalGetSecret = (key) => {
 	if (result.ok) {
 		return result.value;
 	}
-	throw createInvalidVariableError(key, result.type);
+	const type = getEnvFieldType(options);
+	throw createInvalidVariablesError(key, type, result);
 };
 
 setOnSetGetEnv((reset) => {