diff --git a/api/updates.py b/api/updates.py
index 51e383f4..3cf3756f 100644
--- a/api/updates.py
+++ b/api/updates.py
@@ -1899,6 +1899,31 @@ def _agent_gateway_restart_failure_message(target: str, restart_result: dict) ->
     )
 
 
+def _discard_local_changes(path: Path, reset_ref: str) -> bool:
+    """Discard local changes and reset *path* to *reset_ref*."""
+    # Do not use -x: ignored build/cache artifacts should survive force update.
+    _run_git(['checkout', '.'], path)
+    # Best-effort clean: a `git clean -fd` failure is NOT fatal. The
+    # following `reset --hard` overwrites any tracked-file collisions
+    # regardless, and residual untracked files that git can't delete are
+    # harmless. In particular, on Windows a file named after a reserved
+    # device name (nul, con, prn, aux, com1-9, lpt1-9) — which can appear
+    # in the working tree when a shell command redirects to `> nul` under
+    # Git Bash — cannot be removed via the normal Win32 path that git uses,
+    # so `clean` exits non-zero. Aborting the whole force update over that
+    # left users stuck (issue #4914). Log the stderr for diagnostics and
+    # proceed to the reset, which is what actually applies the update.
+    clean_out, clean_ok = _run_git(['clean', '-fd'], path)
+    if not clean_ok:
+        logger.warning(
+            'force_apply_update: `git clean -fd` failed (non-fatal, '
+            'continuing to reset --hard): %s',
+            clean_out,
+        )
+    _, ok = _run_git(['reset', '--hard', reset_ref], path)
+    return ok
+
+
 def apply_force_update(target: str, channel=None) -> dict:
     """Force-reset the target repo to the latest remote HEAD.
 
@@ -1967,13 +1992,16 @@ def apply_force_update(target: str, channel=None) -> dict:
         # force to. Do NOT fall back to origin/master (firehose). See
         # _select_apply_compare_ref channel semantics.
         if compare_ref is None:
-            return {
-                'ok': True,
-                'message': f'{target} is already up to date on the {channel} channel.',
-                'target': target,
-                'up_to_date': True,
-                'channel': channel,
-            }
+            if target == 'webui' and channel == 'stable' and _is_dirty(path):
+                compare_ref = 'HEAD'
+            else:
+                return {
+                    'ok': True,
+                    'message': f'{target} is already up to date on the {channel} channel.',
+                    'target': target,
+                    'up_to_date': True,
+                    'channel': channel,
+                }
 
         # Rewind guard (Codex CORE #3): refuse to reset --hard onto a ref that
         # is an ANCESTOR of HEAD — that would downgrade the checkout. This is the
@@ -1995,28 +2023,7 @@ def apply_force_update(target: str, channel=None) -> dict:
                 'channel': channel,
                 'refused_rewind': True,
             }
-        # Discard local modifications and untracked colliders before resetting.
-        # Do not use -x: ignored build/cache artifacts should survive force update.
-        _run_git(['checkout', '.'], path)
-        # Best-effort clean: a `git clean -fd` failure is NOT fatal. The
-        # following `reset --hard` overwrites any tracked-file collisions
-        # regardless, and residual untracked files that git can't delete are
-        # harmless. In particular, on Windows a file named after a reserved
-        # device name (nul, con, prn, aux, com1-9, lpt1-9) — which can appear
-        # in the working tree when a shell command redirects to `> nul` under
-        # Git Bash — cannot be removed via the normal Win32 path that git uses,
-        # so `clean` exits non-zero. Aborting the whole force update over that
-        # left users stuck (issue #4914). Log the stderr for diagnostics and
-        # proceed to the reset, which is what actually applies the update.
-        clean_out, clean_ok = _run_git(['clean', '-fd'], path)
-        if not clean_ok:
-            logger.warning(
-                'force_apply_update: `git clean -fd` failed (non-fatal, '
-                'continuing to reset --hard): %s',
-                clean_out,
-            )
-        _, ok = _run_git(['reset', '--hard', compare_ref], path)
-        if not ok:
+        if not _discard_local_changes(path, compare_ref):
             return {'ok': False, 'message': f'Force reset to {compare_ref} failed'}
 
         with _cache_lock:
diff --git a/tests/test_updates.py b/tests/test_updates.py
index 88adba1c..bb9dc2af 100644
--- a/tests/test_updates.py
+++ b/tests/test_updates.py
@@ -1,6 +1,7 @@
 """Tests for self-update diagnostics (api/updates.py)."""
 import json
 import os
+import subprocess
 import time
 from unittest.mock import MagicMock, patch
 
@@ -9,6 +10,42 @@ import pytest
 import api.updates as updates
 
 
+def _git(repo, *args):
+    subprocess.run(
+        ['git', *args], cwd=str(repo), check=True,
+        stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+    )
+
+
+def _dirty_stable_repo(tmp_path):
+    repo = tmp_path / 'repo'
+    repo.mkdir()
+    _git(repo, 'init', '-q')
+    _git(repo, 'config', 'user.email', 't@t.co')
+    _git(repo, 'config', 'user.name', 'Test')
+    _git(repo, 'remote', 'add', 'origin', 'https://github.com/nesquena/hermes-webui.git')
+    (repo / '.gitignore').write_text('ignored/\n', encoding='utf-8')
+    tracked = repo / 'tracked.txt'
+    tracked.write_text('stable content\n', encoding='utf-8')
+    _git(repo, 'add', '.gitignore', 'tracked.txt')
+    _git(repo, 'commit', '-q', '-m', 'stable')
+    _git(repo, 'tag', 'v0.52.5')
+    tracked.write_text('experimental content\n', encoding='utf-8')
+    _git(repo, 'commit', '-q', '-am', 'experimental')
+    _git(repo, 'tag', 'exp-v0.52.6')
+    (repo / 'ignored').mkdir()
+    (repo / 'ignored' / 'cache.bin').write_text('keep\n', encoding='utf-8')
+    (repo / 'untracked.txt').write_text('remove\n', encoding='utf-8')
+    tracked.write_text('local modification\n', encoding='utf-8')
+    return repo, tracked
+
+
+@pytest.fixture(autouse=True)
+def _prevent_test_process_restart(monkeypatch):
+    # Keep successful mocked update tests from re-executing pytest on Windows.
+    monkeypatch.setattr(updates, '_schedule_restart', MagicMock())
+
+
 def _fake_git_for_release_fetch_failure(args, cwd, timeout=10):
     if args == ['diff-index', '--quiet', 'HEAD', '--']:
         return '', True  # clean tree
@@ -311,6 +348,178 @@ def test_apply_force_update_fetch_failure_redacts_query_secrets(tmp_path):
     assert '<redacted>' in result['message']
 
 
+def test_force_update_cleans_dirty_stable_checkout_without_changing_head(tmp_path, monkeypatch):
+    repo, tracked = _dirty_stable_repo(tmp_path)
+    head, ok = updates._run_git(['rev-parse', 'HEAD'], repo)
+    assert ok
+    calls = []
+    real_run_git = updates._run_git
+
+    def no_fetch(args, cwd, timeout=10):
+        calls.append(args)
+        if args[:2] == ['fetch', 'origin']:
+            return '', True
+        return real_run_git(args, cwd, timeout=timeout)
+
+    monkeypatch.setattr(updates, 'REPO_ROOT', repo)
+    monkeypatch.setattr(
+        updates, '_restart_blocker_snapshot',
+        lambda: {'restart_blocked': False, 'active_streams': 0, 'active_runs': 0},
+    )
+    restart = MagicMock()
+    monkeypatch.setattr(updates, '_schedule_restart', restart)
+    monkeypatch.setattr(updates, '_run_git', no_fetch)
+
+    result = updates.apply_force_update('webui', channel='stable')
+    status, status_ok = real_run_git(['status', '--porcelain'], repo)
+    after_head, after_head_ok = real_run_git(['rev-parse', 'HEAD'], repo)
+    reset_refs = [args[2] for args in calls if args[:2] == ['reset', '--hard']]
+
+    assert (
+        result == {
+            'ok': True,
+            'message': 'webui force-updated to HEAD',
+            'target': 'webui',
+            'restart_scheduled': True,
+        }
+        and tracked.read_text(encoding='utf-8') == 'experimental content\n'
+        and status_ok and status == ''
+        and after_head_ok and after_head == head
+        and (repo / 'ignored' / 'cache.bin').exists()
+        and not (repo / 'untracked.txt').exists()
+        and reset_refs == ['HEAD']
+        and all(not ref.startswith('origin/') and not ref.startswith('exp-v') for ref in reset_refs)
+    ), (
+        f'result={result!r}, content={tracked.read_text(encoding="utf-8")!r}, '
+        f'status={status!r}, head={after_head!r}, original_head={head!r}, '
+        f'reset_refs={reset_refs!r}, calls={calls!r}'
+    )
+    restart.assert_called_once_with()
+
+
+def test_force_update_clean_stable_no_ref_is_an_exact_noop(tmp_path, monkeypatch):
+    (tmp_path / '.git').mkdir()
+    calls = []
+
+    def fake_git(args, cwd, timeout=10):
+        calls.append(args)
+        if args == ['fetch', 'origin', '--quiet', '--tags', '--force']:
+            return '', True
+        raise AssertionError(f'unexpected git args: {args!r}')
+
+    dirty = MagicMock(return_value=False)
+    monkeypatch.setattr(updates, 'REPO_ROOT', tmp_path)
+    monkeypatch.setattr(
+        updates, '_restart_blocker_snapshot',
+        lambda: {'restart_blocked': False, 'active_streams': 0, 'active_runs': 0},
+    )
+    monkeypatch.setattr(updates, '_select_apply_compare_ref', lambda *args: None)
+    monkeypatch.setattr(updates, '_is_dirty', dirty)
+    monkeypatch.setattr(updates, '_run_git', fake_git)
+    restart = MagicMock()
+    monkeypatch.setattr(updates, '_schedule_restart', restart)
+
+    result = updates.apply_force_update('webui', channel='stable')
+
+    assert result == {
+        'ok': True,
+        'message': 'webui is already up to date on the stable channel.',
+        'target': 'webui',
+        'up_to_date': True,
+        'channel': 'stable',
+    }
+    dirty.assert_called_once_with(tmp_path)
+    assert calls == [['fetch', 'origin', '--quiet', '--tags', '--force']]
+    restart.assert_not_called()
+
+
+def test_force_update_dirty_probe_error_keeps_stable_no_ref_as_an_exact_noop(tmp_path, monkeypatch):
+    (tmp_path / '.git').mkdir()
+    calls = []
+
+    def fake_git(args, cwd, timeout=10):
+        calls.append(args)
+        if args == ['fetch', 'origin', '--quiet', '--tags', '--force']:
+            return '', True
+        if args == ['diff-index', '--quiet', 'HEAD', '--']:
+            return 'fatal: unable to read index', False
+        raise AssertionError(f'unexpected git args: {args!r}')
+
+    monkeypatch.setattr(updates, 'REPO_ROOT', tmp_path)
+    monkeypatch.setattr(
+        updates, '_restart_blocker_snapshot',
+        lambda: {'restart_blocked': False, 'active_streams': 0, 'active_runs': 0},
+    )
+    monkeypatch.setattr(updates, '_select_apply_compare_ref', lambda *args: None)
+    monkeypatch.setattr(updates, '_run_git', fake_git)
+    restart = MagicMock()
+    monkeypatch.setattr(updates, '_schedule_restart', restart)
+
+    result = updates.apply_force_update('webui', channel='stable')
+
+    assert result == {
+        'ok': True,
+        'message': 'webui is already up to date on the stable channel.',
+        'target': 'webui',
+        'up_to_date': True,
+        'channel': 'stable',
+    }
+    assert calls == [
+        ['fetch', 'origin', '--quiet', '--tags', '--force'],
+        ['diff-index', '--quiet', 'HEAD', '--'],
+    ]
+    restart.assert_not_called()
+
+
+@pytest.mark.parametrize('reset_ok', [True, False])
+def test_force_update_clean_failure_preserves_reset_boundary(tmp_path, monkeypatch, reset_ok):
+    (tmp_path / '.git').mkdir()
+    calls = []
+
+    def fake_git(args, cwd, timeout=10):
+        calls.append(args)
+        if args == ['fetch', 'origin', '--quiet', '--tags', '--force']:
+            return '', True
+        if args == ['checkout', '.']:
+            return '', True
+        if args == ['clean', '-fd']:
+            return 'unable to remove untracked file', False
+        if args == ['reset', '--hard', 'origin/main']:
+            return '', reset_ok
+        raise AssertionError(f'unexpected git args: {args!r}')
+
+    monkeypatch.setattr(updates, 'REPO_ROOT', tmp_path)
+    monkeypatch.setattr(
+        updates, '_restart_blocker_snapshot',
+        lambda: {'restart_blocked': False, 'active_streams': 0, 'active_runs': 0},
+    )
+    monkeypatch.setattr(updates, '_select_apply_compare_ref', lambda *args: 'origin/main')
+    monkeypatch.setattr(updates, '_head_contains_ref', lambda *args: False)
+    monkeypatch.setattr(updates, '_run_git', fake_git)
+    restart = MagicMock()
+    monkeypatch.setattr(updates, '_schedule_restart', restart)
+
+    result = updates.apply_force_update('webui', channel='stable')
+
+    assert calls == [
+        ['fetch', 'origin', '--quiet', '--tags', '--force'],
+        ['checkout', '.'],
+        ['clean', '-fd'],
+        ['reset', '--hard', 'origin/main'],
+    ]
+    if reset_ok:
+        assert result == {
+            'ok': True,
+            'message': 'webui force-updated to origin/main',
+            'target': 'webui',
+            'restart_scheduled': True,
+        }
+        restart.assert_called_once_with()
+    else:
+        assert result == {'ok': False, 'message': 'Force reset to origin/main failed'}
+        restart.assert_not_called()
+
+
 def test_check_for_updates_can_skip_agent_repo(tmp_path):
     """Ignoring Agent updates should still check WebUI but avoid touching Agent git."""
     webui_path = tmp_path / 'webui'