diff --git a/references/schemas/nfse/1.01/README.md b/references/schemas/nfse/1.01/README.md
index 5242d77..ee26cb4 100644
--- a/references/schemas/nfse/1.01/README.md
+++ b/references/schemas/nfse/1.01/README.md
@@ -33,6 +33,20 @@ GitHub stores file contents as content-addressed Git blobs. The blob IDs below p
 | `tiposComplexos_v1.01.xsd` | `91f44b804ddcba93c65f7dea923ca4621c1dcd6a` |
 | `tiposSimples_v1.01.xsd` | `6cf3dcb9c085e284a9b78b9a6a4c2688a95df5e9` |
 | `xmldsig-core-schema.xsd` | `8a9c9139d0cb2c3497ce67942ba7d1e8528241d0` |
+| `pedRegEvento_v1.01.xsd` | `d8d3db9afdb2b79d6c32dd6d2ed727dcc6e22a6a` |
+| `tiposEventos_v1.01.xsd` | `1a568683f6cb5e1ca65b5827477d50884409bd43` |
+
+`OfficialSchemaBundleIntegrityTest` recomputes these Git blob identifiers locally in CI. Any byte change to an official schema therefore requires an explicit manifest update and review.
+
+## Updating the official schema bundle
+
+1. Download the new production XSD package from the documented Sistema Nacional NFS-e production documentation page.
+2. Create a new version directory; never overwrite an existing supported snapshot in place.
+3. Copy the official XSD files byte-for-byte. Do not fix upstream schema defects in the reference files.
+4. Add or update validators and representative contract tests for every XML document the library generates for that schema release.
+5. Record the package name, publication date, source URL and Git blob identifiers in the new directory README.
+6. Update the integrity-test manifest and run PHPUnit, static analysis, minimum-dependency and REUSE checks.
+7. Document any deliberate compatibility caveat in the version README and in public migration notes.
 
 When refreshing the official bundle, add a new version directory and update its own manifest instead of replacing this v1.01 snapshot in place.
 
diff --git a/tests/Unit/Xml/OfficialSchemaBundleIntegrityTest.php b/tests/Unit/Xml/OfficialSchemaBundleIntegrityTest.php
new file mode 100644
index 0000000..ca13d67
--- /dev/null
+++ b/tests/Unit/Xml/OfficialSchemaBundleIntegrityTest.php
@@ -0,0 +1,49 @@
+<?php
+
+// SPDX-FileCopyrightText: 2026 LibreCode coop and contributors
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+declare(strict_types=1);
+
+namespace LibreCodeCoop\NfsePHP\Tests\Unit\Xml;
+
+use LibreCodeCoop\NfsePHP\Tests\TestCase;
+
+/**
+ * Guards the vendored official schema snapshot against silent byte changes.
+ */
+final class OfficialSchemaBundleIntegrityTest extends TestCase
+{
+    /**
+     * @var array<string, string>
+     */
+    private const EXPECTED_GIT_BLOBS = [
+        'DPS_v1.01.xsd' => '39f440dd46db4e15a378b60910a3ac0baf19e476',
+        'tiposComplexos_v1.01.xsd' => '91f44b804ddcba93c65f7dea923ca4621c1dcd6a',
+        'tiposSimples_v1.01.xsd' => '6cf3dcb9c085e284a9b78b9a6a4c2688a95df5e9',
+        'xmldsig-core-schema.xsd' => '8a9c9139d0cb2c3497ce67942ba7d1e8528241d0',
+        'pedRegEvento_v1.01.xsd' => 'd8d3db9afdb2b79d6c32dd6d2ed727dcc6e22a6a',
+        'tiposEventos_v1.01.xsd' => '1a568683f6cb5e1ca65b5827477d50884409bd43',
+    ];
+
+    public function testOfficialSchemaFilesMatchTheDocumentedSnapshot(): void
+    {
+        $schemaDirectory = dirname(__DIR__, 3) . '/references/schemas/nfse/1.01';
+
+        foreach (self::EXPECTED_GIT_BLOBS as $file => $expectedBlob) {
+            $path = $schemaDirectory . '/' . $file;
+            self::assertFileExists($path);
+
+            $contents = file_get_contents($path);
+            self::assertIsString($contents);
+
+            $actualBlob = sha1('blob ' . strlen($contents) . "\0" . $contents);
+
+            self::assertSame(
+                $expectedBlob,
+                $actualBlob,
+                'Official schema changed without an explicit integrity-manifest update: ' . $file,
+            );
+        }
+    }
+}