diff --git a/scripts/live-config-guard.cjs b/scripts/live-config-guard.cjs
index e6793fff4..9a118a391 100644
--- a/scripts/live-config-guard.cjs
+++ b/scripts/live-config-guard.cjs
@@ -61,8 +61,20 @@ const fs = require('fs');
 const os = require('os');
 const path = require('path');
 
-/** Top-level entries only a GSD install creates. See SCOPE above before widening. */
-const GSD_OWNED_ENTRIES = ['gsd-core', 'gsd-file-manifest.json', 'gsd-pristine'];
+/**
+ * Top-level entries only a GSD install creates. See SCOPE above before widening.
+ *
+ * `.gsd-source` and `.gsd-profile` were added by the round-5 census (see below):
+ * bin/install.js writes both at the config ROOT for a global install, and an
+ * exact-name list does not match a dot-prefixed name by the `gsd-` prefix rule.
+ */
+const GSD_OWNED_ENTRIES = [
+  'gsd-core',
+  'gsd-file-manifest.json',
+  'gsd-pristine',
+  '.gsd-source',
+  '.gsd-profile',
+];
 
 /**
  * Directories GSD SHARES with the host agent. Watching them wholesale would
@@ -73,8 +85,16 @@ const GSD_OWNED_ENTRIES = ['gsd-core', 'gsd-file-manifest.json', 'gsd-pristine']
  * `spawnSync` that sandboxed HOME but inherited an ambient CLAUDE_CONFIG_DIR
  * wrote `<live>/skills/gsd-dev-preferences/SKILL.md`, which sits under none of
  * the three top-level entries above.
+ *
+ * `hooks` joined them in round 5, found by re-deriving the census rather than by
+ * a review finding — the SAME shape one parent over. bin/install.js writes
+ * `hooks/gsd-check-update.js`, `hooks/gsd-context-monitor.js` and
+ * `hooks/gsd-update-banner.js` into the config root, and with `hooks` absent from
+ * this list a leak of any of them passed the guard silently. The lesson the first
+ * miss taught is that this list is the weak point, so it is re-derived from the
+ * installer's own write sites each round rather than trusted.
  */
-const GSD_PREFIXED_PARENTS = ['agents', 'commands', 'skills'];
+const GSD_PREFIXED_PARENTS = ['agents', 'commands', 'skills', 'hooks'];
 const GSD_ARTIFACT_PREFIX = 'gsd-';
 
 /**
diff --git a/tests/live-config-guard.test.cjs b/tests/live-config-guard.test.cjs
index 6514949ea..bfe07fc0c 100644
--- a/tests/live-config-guard.test.cjs
+++ b/tests/live-config-guard.test.cjs
@@ -190,6 +190,46 @@ describe('#2665: live-config hermeticity guard', () => {
     }
   });
 
+  test('detects a leaked hook script and the install marker files', () => {
+    // Self-found by re-deriving the census at round 5 rather than by a review
+    // finding. bin/install.js writes hooks/gsd-*.js, .gsd-source and .gsd-profile
+    // into the config ROOT; `hooks` was absent from GSD_PREFIXED_PARENTS and the
+    // two dot-prefixed markers from GSD_OWNED_ENTRIES, so all three leaked past
+    // the guard silently -- the same shape as the skills/gsd-dev-preferences miss
+    // that motivated the prefixed-parent scan in the first place.
+    const root = tmpRoot();
+    try {
+      fs.mkdirSync(path.join(root, 'hooks'), { recursive: true });
+      const before = snapshotLiveConfig([root]);
+      fs.writeFileSync(path.join(root, 'hooks', 'gsd-check-update.js'), '// x');
+      fs.writeFileSync(path.join(root, '.gsd-source'), 'npm');
+      fs.writeFileSync(path.join(root, '.gsd-profile'), 'default');
+
+      const created = diffLiveConfig(before, snapshotLiveConfig([root]))
+        .filter((v) => v.kind === 'created')
+        .map((v) => path.basename(v.path))
+        .sort();
+      assert.deepStrictEqual(created, ['.gsd-profile', '.gsd-source', 'gsd-check-update.js']);
+    } finally {
+      cleanup(root);
+    }
+  });
+
+  test('a NON-gsd hook belonging to the host agent is still ignored', () => {
+    // Widening GSD_PREFIXED_PARENTS must not widen ownership: `hooks/` is shared
+    // with the host agent, and a guard that flags its files gets switched off.
+    const root = tmpRoot();
+    try {
+      fs.mkdirSync(path.join(root, 'hooks'), { recursive: true });
+      const before = snapshotLiveConfig([root]);
+      fs.writeFileSync(path.join(root, 'hooks', 'my-own-hook.js'), '// mine');
+
+      assert.deepStrictEqual(diffLiveConfig(before, snapshotLiveConfig([root])), []);
+    } finally {
+      cleanup(root);
+    }
+  });
+
   test('detects a DELETED top-level GSD entry', () => {
     const root = tmpRoot();
     try {