diff --git a/packages/next/src/server/web/spec-extension/revalidate.ts b/packages/next/src/server/web/spec-extension/revalidate.ts
index da9c2b4bf7..a44cd266ad 100644
--- a/packages/next/src/server/web/spec-extension/revalidate.ts
+++ b/packages/next/src/server/web/spec-extension/revalidate.ts
@@ -21,7 +21,7 @@ type CacheLifeConfig = {
  *
  * Read more: [Next.js Docs: `revalidateTag`](https://nextjs.org/docs/app/api-reference/functions/revalidateTag)
  */
-export function revalidateTag(tag: string, profile: string | CacheLifeConfig) {
+export function revalidateTag(tag: string, profile?: string | CacheLifeConfig) {
   if (!profile) {
     console.warn(
       '"revalidateTag" without the second argument is now deprecated, add second argument of "max" or use "updateTag". See more info here: https://nextjs.org/docs/messages/revalidate-tag-single-arg'

Analysis

TypeScript signature for revalidateTag incorrectly marks profile parameter as required

What fails: The revalidateTag() function signature in packages/next/src/server/web/spec-extension/revalidate.ts (line 24) requires the profile parameter, but the documentation and runtime behavior indicate it should be optional. This causes TypeScript type errors when calling revalidateTag(tag) without the second argument, even though it's a valid (albeit deprecated) usage pattern.

How to reproduce:

import { revalidateTag } from 'next/cache'

// This matches the documented behavior and runtime behavior,
// but TypeScript complains with error TS2554:
// "Expected 2 arguments, but got 1"
revalidateTag('posts')

// This works without error:
revalidateTag('posts', 'max')

Evidence:

• Documentation shows signature: revalidateTag(tag: string, profile?: string | { expire?: number }): void - note the ? marker
• Implementation shows signature: export function revalidateTag(tag: string, profile: string | CacheLifeConfig) - no ? marker
• Runtime behavior accepts undefined: if (!profile) { console.warn(...) } explicitly handles the missing case
• Test file at test/e2e/app-dir/app-static/app/update-tag-test/actions.ts contains @ts-expect-error comment before calling revalidateTag('test-update-tag') without second argument, confirming the type mismatch

Result: TypeScript incorrectly enforces that the second argument is required when it should be optional

Expected: The TypeScript function signature should match the documentation and runtime behavior by marking profile as optional with the ? marker: export function revalidateTag(tag: string, profile?: string | CacheLifeConfig)

Fix applied: Added optional marker ? to the profile parameter in the function signature at packages/next/src/server/web/spec-extension/revalidate.ts line 24