diff --git a/docs/TESTING.md b/docs/TESTING.md
index 136aae8d1c..e258d78cfc 100644
--- a/docs/TESTING.md
+++ b/docs/TESTING.md
@@ -39,7 +39,8 @@ See `test/e2e/AGENTS.md` for the full E2E testing guide (setup, writing tests, c
 
 Quick commands:
 
-- `yarn test:e2e:setup` — first-time setup
+- `yarn test:e2e:setup` — first-time setup (builds packages and apps, then installs browsers for the workspace Playwright version)
+- `yarn test:e2e:setup:pinned` — optional; installs Chromium, Firefox, and WebKit for Playwright **1.40.1** (required to run the `firefox-pinned` and `webkit-pinned` projects; run after the usual setup when you need those projects locally)
 - `yarn test:e2e` — run all E2E tests
 - `yarn test:e2e -g "pattern"` — filter by name
 - `yarn test:e2e --ui` — Playwright UI mode
@@ -53,6 +54,8 @@ translation proxy. Run them with:
 - `yarn test:e2e --project=firefox-pinned`
 - `yarn test:e2e --project=webkit-pinned`
 
+If those projects fail because browsers are missing, run `yarn test:e2e:setup:pinned` once so the Playwright 1.40.1 browser binaries are installed alongside the default setup.
+
 ## Run unit tests in BrowserStack
 
 - `BS_USERNAME=<username> BS_ACCESS_KEY=<access_key> yarn test:unit:bs`
diff --git a/package.json b/package.json
index 29aa8ae74d..7589a45e3b 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,8 @@
     "test:script": "node --test --experimental-test-module-mocks './scripts/**/*.spec.*'",
     "test:unit:watch": "yarn test:unit --no-single-run",
     "test:unit:bs": "node --env-file-if-exists=.env ./scripts/test/bs-wrapper.ts karma start test/unit/karma.bs.conf.js",
-    "test:e2e:setup": "yarn build && yarn build:apps && yarn playwright install --with-deps && yarn dlx -p playwright@1.40.1 playwright install chromium firefox webkit",
+    "test:e2e:setup": "yarn build && yarn build:apps && yarn playwright install --with-deps",
+    "test:e2e:setup:pinned": "volta run --node 20 yarn dlx -p playwright@1.40.1 playwright install chromium firefox webkit",
     "test:e2e": "playwright test --config test/e2e/playwright.config.ts",
     "test:compat:tsc": "node scripts/check-typescript-compatibility.ts",
     "test:compat:ssr": "scripts/cli check_server_side_rendering_compatibility",
diff --git a/test/e2e/AGENTS.md b/test/e2e/AGENTS.md
index f35da9f330..7b8e555dd6 100644
--- a/test/e2e/AGENTS.md
+++ b/test/e2e/AGENTS.md
@@ -5,9 +5,14 @@ E2E tests use Playwright to test the SDK in real browser environments.
 ## Running E2E Tests
 
 ```bash
-# First time setup (builds packages, apps, installs or updates Playwright browsers)
+# First-time setup: builds packages and apps; installs or updates Playwright browsers
+# for the workspace Playwright version.
 yarn test:e2e:setup
 
+# Optional: install Chromium, Firefox, and WebKit for Playwright 1.40.1. Required
+# locally if you run the firefox-pinned / webkit-pinned projects (see docs/TESTING.md).
+yarn test:e2e:setup:pinned
+
 # Run E2E tests locally
 yarn test:e2e