diff --git a/demo/benchmark_glow.mjs b/demo/benchmark_glow.mjs
index 3c08a929..f61019b1 100644
--- a/demo/benchmark_glow.mjs
+++ b/demo/benchmark_glow.mjs
@@ -87,7 +87,7 @@ const viewport = { width: 1280, height: 900 };
 const { page, browser } = await launch(
   viewport, 1,
   ['--enable-precise-memory-info', '--js-flags=--expose-gc'],
-  {}, resolve(targetRoot, 'demo/srv'),
+  {}, resolve(targetRoot, 'demo/srv'), targetRoot,
 );
 await page.addScriptTag({
   content: `window.__hpAssertCardContract = ${assertCardContract.toString()};`,
diff --git a/demo/benchmark_large_house.mjs b/demo/benchmark_large_house.mjs
index 500dfefd..9406baa0 100644
--- a/demo/benchmark_large_house.mjs
+++ b/demo/benchmark_large_house.mjs
@@ -43,6 +43,7 @@ const { page, browser } = await launch(
   ['--enable-precise-memory-info', '--js-flags=--expose-gc'],
   {},
   resolve(targetRoot, 'demo/srv'),
+  targetRoot,
 );
 await page.emulateMedia({ reducedMotion: 'reduce' });
 await page.addStyleTag({
diff --git a/demo/serve.mjs b/demo/serve.mjs
index 88a0af64..5471ebc0 100644
--- a/demo/serve.mjs
+++ b/demo/serve.mjs
@@ -50,6 +50,7 @@ export async function launch(
   browserArgs = [],
   contextOptions = {},
   serveRoot = ROOT,
+  repoRoot = REPO_ROOT,
 ) {
   const browser = await chromium.launch({ args: ['--no-sandbox', ...browserArgs] });
   const page = await (await browser.newContext({
@@ -75,7 +76,7 @@ export async function launch(
   // круга разбора: три проверки упали, четвёртая ложно прошла, поскольку старый
   // код одинаково врал в двух местах, которые сверялись друг с другом.
   // golden и бенчмарки эту защиту имели с самого начала, смоки — нет.
-  await assertFreshDemoBundleUnlessAllowed(page, REPO_ROOT);
+  await assertFreshDemoBundleUnlessAllowed(page, repoRoot);
   // HP-1552: the first-open boot veil hides the plan (visibility:hidden) until
   // the stage height settles — real pointer interaction cannot hit a hidden
   // plan, so every smoke starts where the user does: with the plan revealed.
diff --git a/docs/DEVELOPMENT.md b/docs/DEVELOPMENT.md
index 249d0504..9b8163bb 100644
--- a/docs/DEVELOPMENT.md
+++ b/docs/DEVELOPMENT.md
@@ -158,7 +158,9 @@ limits. See
 When the comparison base predates `scripts/bundle-sync.mjs`, the workflow still
 builds that exact tree and materializes its fresh bundle through the equivalent
 legacy copy path. This keeps old stable releases usable as performance baselines
-without borrowing build output from the candidate.
+without borrowing build output from the candidate. Comparative benchmark
+launches also pass that target tree as the freshness authority; the ordinary
+smoke launcher continues to default to the current repository root.
 Both browser diagnostics require a freshly built/copied demo bundle. Rollup
 embeds a SHA-256 fingerprint of `src/` plus the locked package and
 Rollup/TypeScript build inputs; benchmark/golden runners fail before
diff --git a/test/bundle-freshness.test.mjs b/test/bundle-freshness.test.mjs
index 1b4a1d05..a8771224 100644
--- a/test/bundle-freshness.test.mjs
+++ b/test/bundle-freshness.test.mjs
@@ -123,6 +123,14 @@ test('the smoke launcher enforces the gate on the repository root (#236)', async
   const source = readFileSync(
     new URL('../demo/serve.mjs', import.meta.url), 'utf8',
   );
-  assert.match(source, /assertFreshDemoBundleUnlessAllowed\(page, REPO_ROOT\)/);
+  assert.match(source, /repoRoot = REPO_ROOT/);
+  assert.match(source, /assertFreshDemoBundleUnlessAllowed\(page, repoRoot\)/);
   assert.match(source, /const REPO_ROOT = dirname\(dirname\(/);
 });
+
+test('comparative benchmarks pass the target repository root to the launcher', () => {
+  for (const file of ['benchmark_large_house.mjs', 'benchmark_glow.mjs']) {
+    const source = readFileSync(new URL(`../demo/${file}`, import.meta.url), 'utf8');
+    assert.match(source, /resolve\(targetRoot, 'demo\/srv'\)[\s\S]{0,40}targetRoot/);
+  }
+});