diff --git a/AGENTS.md b/AGENTS.md
index 43cc0e4..e4da980 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -29,7 +29,7 @@ npm run smoke          # load the ESM, CJS, and IIFE builds; requires dist/
 npm run check          # format, lint, typecheck, build, test, smoke, publint
 ```
 
-Node.js **24+**. Run `npm run check` before handing work back. Run `npm run test:coverage` when you add or change an executable `src/` file. `src/index.ts`, `src/runtime/types.ts`, and `src/templates/email/types.ts` are excluded: v8 reports 0% on files with no runtime code.
+Node.js **24+**. Run `npm run check` before handing work back. Run `npm run test:coverage` when you add or change an executable `src/` file. `src/index.ts`, `src/runtime/types.ts`, `src/templates/email/types.ts`, and `src/templates/document/index.ts` are excluded: v8 reports 0% on files with no runtime code.
 
 ESLint and Prettier both run in CI. Tests are Vitest, not Jest. `markup-generator` is a devDependency used to write rendered HTML in `test/write.test.ts` and `npm run generate`. It is not a runtime dependency.
 
diff --git a/test/email.test.ts b/test/email.test.ts
index 5ca472d..449ff59 100644
--- a/test/email.test.ts
+++ b/test/email.test.ts
@@ -149,10 +149,15 @@ describe('renderEmail', () => {
         bodyAttributes: 'style="margin:0"',
       },
     });
-    const html = renderEmail(template, { title: 'Hi', bodyAttributes: 'style="padding:0"' }).html;
-    expect(html).toMatch(/^<!DOCTYPE html PUBLIC/);
-    expect(html).toContain('<html xmlns="http://www.w3.org/1999/xhtml">');
-    expect(html).not.toContain('lang=');
+    const html = renderEmail(template, {
+      title: 'Hi',
+      doctype: '<!DOCTYPE html>',
+      lang: 'fr',
+      htmlAttributes: 'class="override"',
+      bodyAttributes: 'style="padding:0"',
+    }).html;
+    expect(html).toMatch(/^<!DOCTYPE html>/);
+    expect(html).toContain('<html lang="fr" class="override">');
     expect(html).toContain('<body style="padding:0">');
   });
 
diff --git a/test/index.test.ts b/test/index.test.ts
index 218147f..5d6dbaa 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -97,12 +97,13 @@ describe('document', () => {
   it('accepts structured attributes on html and body', () => {
     const html = document({
       lang: false,
-      htmlAttributes: { xmlns: 'http://www.w3.org/1999/xhtml', class: 'email' },
-      bodyAttributes: { style: 'margin:0', 'data-theme': 'light' },
+      htmlAttributes: { xmlns: 'http://www.w3.org/1999/xhtml', class: 'email', hidden: true },
+      bodyAttributes: { style: 'margin:0', 'data-theme': 'light', disabled: false },
       mainHtml: '<p>Hi</p>',
     });
-    expect(html).toContain('<html xmlns="http://www.w3.org/1999/xhtml" class="email">');
+    expect(html).toContain('<html xmlns="http://www.w3.org/1999/xhtml" class="email" hidden>');
     expect(html).toContain('<body style="margin:0" data-theme="light">');
+    expect(html).not.toContain('disabled');
   });
 
   it('supports body attributes and omitting lang (good-news style)', () => {
diff --git a/vitest.config.ts b/vitest.config.ts
index 6b26b4d..414a8b3 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -9,7 +9,12 @@ export default defineConfig({
       provider: 'v8',
       reporter: ['text', 'html'],
       include: ['src/**/*.ts'],
-      exclude: ['src/index.ts', 'src/runtime/types.ts', 'src/templates/email/types.ts'],
+      exclude: [
+        'src/index.ts',
+        'src/runtime/types.ts',
+        'src/templates/email/types.ts',
+        'src/templates/document/index.ts',
+      ],
       thresholds: {
         statements: 100,
         branches: 100,