diff --git a/docs/releasing.md b/docs/releasing.md
index fb2a246..4a9710e 100644
--- a/docs/releasing.md
+++ b/docs/releasing.md
@@ -21,7 +21,7 @@ The site is a static Astro build deployed by Vercel's Git integration. Its setti
 
 1. In Vercel, choose **Add New → Project** and import `samarthmn/echo-voice-web`.
 2. Set the **Root Directory** to `site`, and keep **Include files outside the root directory in the Build Step** enabled: the site reads `docs/`, `brand/`, `public/fonts/` and `scripts/` from the repository root.
-3. Leave the framework, install and build settings to `site/vercel.json` (Astro; `pnpm install --frozen-lockfile --filter echo-site`; `pnpm build`; output `dist`).
+3. Leave the framework, install and build settings to `site/vercel.json` (Astro; output `dist`). It runs the repository's pinned pnpm (12.11.2) through `npx` for install and build, because Vercel's bundled pnpm cannot switch itself to pnpm 12. Keep that version in step with `packageManager` in `package.json`.
 4. Under **Settings → General**, choose Node.js 22 or newer.
 5. Under **Settings → Domains**, add `echo-web.samarthmn.com` and create the DNS record Vercel shows.
 6. Under **Analytics**, enable Web Analytics. Builds on Vercel then include its cookieless script, served from the site's own `/_vercel/insights` path. Analytics only ever run on the website, never in the app.
diff --git a/site/vercel.json b/site/vercel.json
index df5b48a..8022d83 100644
--- a/site/vercel.json
+++ b/site/vercel.json
@@ -1,8 +1,8 @@
 {
   "$schema": "https://openapi.vercel.sh/vercel.json",
   "framework": "astro",
-  "installCommand": "pnpm install --frozen-lockfile --filter echo-site",
-  "buildCommand": "pnpm build",
+  "installCommand": "npx --yes pnpm@12.11.2 install --frozen-lockfile --filter echo-site",
+  "buildCommand": "npx --yes pnpm@12.11.2 run build",
   "outputDirectory": "dist",
   "trailingSlash": true,
   "headers": [