diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..a7f95a9
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,6 @@
+# The vendored Playwright client is verified by a byte-exact SHA-256 digest
+# (scripts/build-playwright-sandbox-client.mjs), and the generated bundle is
+# byte-compared against a fresh esbuild output. Both must therefore check out
+# identically on every platform, regardless of core.autocrlf.
+src/browser/run/playwright-client/vendor/** text eol=lf
+src/browser/run/generated/playwright-client.js text eol=lf
diff --git a/scripts/build-playwright-sandbox-client.mjs b/scripts/build-playwright-sandbox-client.mjs
index 4e58a16..46b6ab2 100644
--- a/scripts/build-playwright-sandbox-client.mjs
+++ b/scripts/build-playwright-sandbox-client.mjs
@@ -1,7 +1,7 @@
 import { createHash } from 'node:crypto';
 import { mkdtemp, readFile, readdir, rm } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
-import { join } from 'node:path';
+import { join, sep } from 'node:path';
 import { build } from 'esbuild';
 
 const output = 'src/browser/run/generated/playwright-client.js';
@@ -24,7 +24,7 @@ async function vendorDigest(directory) {
   await walk(directory);
   const hash = createHash('sha256');
   for (const file of files.sort()) {
-    const entry = file.slice(directory.length + 1);
+    const entry = file.slice(directory.length + 1).split(sep).join('/');
     hash.update(entry);
     hash.update('\0');
     hash.update(await readFile(file));
diff --git a/vitest.config.ts b/vitest.config.ts
index 45b8347..8a7df98 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -23,7 +23,6 @@ export default defineConfig({
         test: {
           name: 'unit',
           include: ['src/**/*.test.ts'],
-          exclude: ['src/browser/**/*.test.ts'],
           sequence: { groupOrder: 0 },
         },
       },