diff --git a/.changeset/preview-base-trailing-slash-redirect.md b/.changeset/preview-base-trailing-slash-redirect.md
new file mode 100644
index 000000000000..0542629ed4f5
--- /dev/null
+++ b/.changeset/preview-base-trailing-slash-redirect.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: preserve `paths.base` when `vite preview` redirects a prerendered page to the correct trailing slash
diff --git a/packages/kit/src/exports/vite/preview/index.js b/packages/kit/src/exports/vite/preview/index.js
index c16b7ef2e8cf..16dc18c45dbd 100644
--- a/packages/kit/src/exports/vite/preview/index.js
+++ b/packages/kit/src/exports/vite/preview/index.js
@@ -9,6 +9,7 @@ import sirv from 'sirv';
 import { loadEnv, normalizePath } from 'vite';
 import { createReadableStream, getRequest, setResponse } from '../../../exports/node/index.js';
 import { SVELTE_KIT_ASSETS } from '../../../constants.js';
+import { relative_pathname } from '../../../utils/url.js';
 import { is_chrome_devtools_request, not_found } from '../utils.js';
 import { stackless } from '../../../utils/error.js';
 
@@ -176,9 +177,9 @@ export async function preview(vite, vite_config, svelte_config) {
 					}
 
 					if (redirect) {
-						if (search) redirect += search;
-						res.writeHead(307, {
-							location: redirect
+						res.writeHead(308, {
+							// relative so (possibly invisible) path prefixes are preserved
+							location: relative_pathname(pathname, redirect) + search
 						});
 
 						res.end();
diff --git a/packages/kit/test/apps/options-2/test/test.js b/packages/kit/test/apps/options-2/test/test.js
index 21ab3a7a1fd5..b39253268b25 100644
--- a/packages/kit/test/apps/options-2/test/test.js
+++ b/packages/kit/test/apps/options-2/test/test.js
@@ -129,6 +129,19 @@ test.describe('trailing slash', () => {
 		await clicknav('a[href="/basepath/trailing-slash-server/prerender"]');
 		await expect(page.locator('h2')).toHaveText('/basepath/trailing-slash-server/prerender/');
 	});
+
+	test('normalizes the trailing slash of a prerendered page without dropping the base', async ({
+		request
+	}) => {
+		const response = await request.get('/basepath/trailing-slash-server/prerender');
+		expect(new URL(response.url()).pathname).toBe('/basepath/trailing-slash-server/prerender/');
+		expect(response.status()).toBe(200);
+
+		const redirect = await request.get('/basepath/trailing-slash-server/prerender', {
+			maxRedirects: 0
+		});
+		expect(redirect.status()).toBe(308);
+	});
 });
 
 test.describe('Service worker', () => {