diff --git a/scripts/autorun.py b/scripts/autorun.py
index 9ee2cfac7..9632f4f61 100644
--- a/scripts/autorun.py
+++ b/scripts/autorun.py
@@ -43,6 +43,7 @@ import shlex
 import shutil
 import subprocess
 import sys
+import tempfile
 import time
 from collections.abc import Callable, Iterator, Sequence
 from dataclasses import dataclass, field
@@ -73,11 +74,6 @@ HOST_MISREAD_MARKERS = ("SystemError", "unknown opcode")
 VOLATILE_KEYS = frozenset({"generated_at", "generated", "imported_at"})
 
 SUBJECT_TYPES = re.compile(r"^(feat|refactor|chore|docs|fix): [a-z0-9]")
-FORBIDDEN_WORDS = re.compile(
-    r"\b(bug|regression|revert|dead code|broken|wrong|hack|workaround|"
-    r"comprehensive|implement)",
-    re.IGNORECASE,
-)
 CI_RED = frozenset({"failure", "timed_out", "startup_failure"})
 CI_GREEN = frozenset({"success", "skipped", "neutral"})
 
@@ -190,16 +186,32 @@ class Context:
 
 
 def check_subject(subject: str, body: str = "") -> list[str]:
-    """What the repository's commit-msg hook would refuse in this message."""
+    """What the repository's commit-msg hook would refuse in this message.
+
+    The hook holds the vocabulary rules, so they live in one place: a job
+    list is checked against it when it loads, not two hours into the job.
+    Without a hook (another clone) only the shape is checked.
+    """
     problems = []
     if len(subject) > 50:
         problems.append(f"subject is {len(subject)} characters, 50 at most")
     if not SUBJECT_TYPES.match(subject):
         problems.append("subject must read 'type: description'")
-    if FORBIDDEN_WORDS.search(f"{subject}\n{body}"):
-        problems.append("message uses a word the history does not carry")
     if re.search(r"^co-authored-by", body, re.IGNORECASE | re.MULTILINE):
         problems.append("no Co-Authored-By trailer")
+    hook = subprocess.run(["git", "rev-parse", "--git-path", "hooks/commit-msg"],
+                          capture_output=True, text=True, cwd=REPO_ROOT, check=False).stdout.strip()
+    hook_path = (REPO_ROOT / hook) if hook else None
+    if hook_path and hook_path.is_file() and os.access(hook_path, os.X_OK):
+        with tempfile.NamedTemporaryFile("w", suffix=".msg", delete=False) as message:
+            message.write(f"{subject}\n\n{body}\n" if body else f"{subject}\n")
+        try:
+            refused = subprocess.run([str(hook_path), message.name], capture_output=True,
+                                     text=True, check=False)
+        finally:
+            os.unlink(message.name)
+        if refused.returncode:
+            problems.append((refused.stderr or refused.stdout).strip() or "refused by commit-msg")
     return problems
 
 
diff --git a/tests/test_autorun.py b/tests/test_autorun.py
index 72bd0687e..0edaf2388 100644
--- a/tests/test_autorun.py
+++ b/tests/test_autorun.py
@@ -17,6 +17,7 @@ import sys
 import tempfile
 import time
 import unittest
+import unittest.mock
 from pathlib import Path
 
 REPO_ROOT = Path(__file__).resolve().parents[1]
@@ -834,5 +835,29 @@ class BiosIntegrity(Scratch):
         return str(self.tmp / "database.json")
 
 
+class SubjectsFollowTheRepositoryHook(unittest.TestCase):
+    """The vocabulary rules live in the commit-msg hook alone: a copy in the
+    runner put the very words the history refuses into a tracked file."""
+
+    def test_a_refusal_comes_from_the_hook(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            hook = Path(tmp) / "commit-msg"
+            hook.write_text('#!/bin/sh\ngrep -q forbiddenword "$1" && echo refused && exit 1\nexit 0\n')
+            hook.chmod(0o755)
+            real = subprocess.run
+            def fake(argv, *args, **kwargs):
+                if argv[:3] == ["git", "rev-parse", "--git-path"]:
+                    return subprocess.CompletedProcess(argv, 0, stdout=str(hook) + "\n", stderr="")
+                return real(argv, *args, **kwargs)
+            with unittest.mock.patch.object(ar.subprocess, "run", side_effect=fake):
+                self.assertEqual(ar.check_subject("chore: tidy the cache"), [])
+                self.assertEqual(ar.check_subject("chore: add forbiddenword"), ["refused"])
+
+    def test_the_shape_is_checked_without_a_hook(self):
+        problems = ar.check_subject("not a subject that follows the type rule at all, too long")
+        self.assertTrue(any("50 at most" in p for p in problems))
+        self.assertTrue(any("type: description" in p for p in problems))
+
+
 if __name__ == "__main__":
     unittest.main()