diff --git a/pre-upload.py b/pre-upload.py
index bdacbec..e06b808 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -2063,23 +2063,34 @@
 
   valid_keys = set(_HOOK_FLAGS.keys())
   hooks = _HOOK_FLAGS.copy()
-  options = config.options(SECTION) if config.has_section(SECTION) else []
+  hook_overrides = set(
+      config.options(SECTION) if config.has_section(SECTION) else [])
+
+  unknown_keys = hook_overrides - valid_keys
+  if unknown_keys:
+    raise ValueError(f'{_CONFIG_FILE}: [{SECTION}]: unknown keys: '
+                     f'{unknown_keys}')
 
   enable_flags = []
   disable_flags = []
-  for flag in options:
-    if flag not in valid_keys:
-      raise ValueError('Error: unknown key "%s" in hook section of "%s"' %
-                       (flag, _CONFIG_FILE))
+  for flag in valid_keys:
+    if flag in hook_overrides:
+      try:
+        enabled = config.getboolean(SECTION, flag)
+      except ValueError as e:
+        raise ValueError('Error: parsing flag "%s" in "%s" failed: %s' %
+                         (flag, _CONFIG_FILE, e))
+    elif hooks[flag] in _COMMON_HOOKS:
+      # Enable common hooks by default so we process custom options below.
+      enabled = True
+    else:
+      # All other hooks we left as a tristate.  We use this below for a few
+      # hooks to control default behavior.
+      enabled = None
 
-    try:
-      enabled = config.getboolean(SECTION, flag)
-    except ValueError as e:
-      raise ValueError('Error: parsing flag "%s" in "%s" failed: %s' %
-                       (flag, _CONFIG_FILE, e))
     if enabled:
       enable_flags.append(flag)
-    else:
+    elif enabled is not None:
       disable_flags.append(flag)
 
     # See if this hook has custom options.
diff --git a/pre-upload_unittest.py b/pre-upload_unittest.py
index 7613973..0702f54 100755
--- a/pre-upload_unittest.py
+++ b/pre-upload_unittest.py
@@ -8,6 +8,7 @@
 
 from __future__ import print_function
 
+import configparser
 import datetime
 import os
 import sys
@@ -1862,5 +1863,112 @@
     self.assertTrue(called)
 
 
+class OverrideHooksProcessing(PreUploadTestCase):
+  """Verify _get_override_hooks processing."""
+
+  @staticmethod
+  def parse(data):
+    """Helper to create a config & parse it."""
+    cfg = configparser.ConfigParser()
+    cfg.read_string(data)
+    return pre_upload._get_override_hooks(cfg)
+
+  def testHooks(self):
+    """Verify we reject unknown hook names (e.g. typos)."""
+    with self.assertRaises(ValueError) as e:
+      self.parse("""
+[Hook Overrides]
+foobar: true
+""")
+    self.assertIn('foobar', str(e.exception))
+
+  def testImplicitDisable(self):
+    """Verify non-common hooks aren't enabled by default."""
+    enabled, _ = self.parse('')
+    self.assertNotIn(pre_upload._run_checkpatch, enabled)
+
+  def testExplicitDisable(self):
+    """Verify hooks disabled are disabled."""
+    _, disabled = self.parse("""
+[Hook Overrides]
+tab_check: false
+""")
+    self.assertIn(pre_upload._check_no_tabs, disabled)
+
+  def testExplicitEnable(self):
+    """Verify hooks enabled are enabled."""
+    enabled, _ = self.parse("""
+[Hook Overrides]
+tab_check: true
+""")
+    self.assertIn(pre_upload._check_no_tabs, enabled)
+
+  def testOptions(self):
+    """Verify hook options are loaded."""
+    enabled, _ = self.parse("""
+[Hook Overrides Options]
+keyword_check: --kw
+""")
+    for func in enabled:
+      if func.__name__ == 'keyword_check':
+        self.assertIn('options', func.keywords)
+        self.assertEqual(func.keywords['options'], ['--kw'])
+        break
+    else:
+      self.fail('could not find "keyword_check" enabled hook')
+
+  def testSignOffField(self):
+    """Verify signoff field handling."""
+    # Enforce no s-o-b by default.
+    enabled, disabled = self.parse('')
+    self.assertIn(pre_upload._check_change_has_no_signoff_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_signoff_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_signoff_field, disabled)
+
+    # If disabled, don't enforce either policy.
+    enabled, disabled = self.parse("""
+[Hook Overrides]
+signoff_check: false
+""")
+    self.assertNotIn(pre_upload._check_change_has_no_signoff_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_signoff_field, enabled)
+    self.assertIn(pre_upload._check_change_has_signoff_field, disabled)
+
+    # If enabled, require s-o-b.
+    enabled, disabled = self.parse("""
+[Hook Overrides]
+signoff_check: true
+""")
+    self.assertNotIn(pre_upload._check_change_has_no_signoff_field, enabled)
+    self.assertIn(pre_upload._check_change_has_signoff_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_signoff_field, disabled)
+
+  def testBranchField(self):
+    """Verify branch field enabling."""
+    # Should be disabled by default.
+    enabled, disabled = self.parse('')
+    self.assertIn(pre_upload._check_change_has_no_branch_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_branch_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_branch_field, disabled)
+
+    # Should be disabled if requested.
+    enabled, disabled = self.parse("""
+[Hook Overrides]
+branch_check: false
+""")
+    self.assertIn(pre_upload._check_change_has_no_branch_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_branch_field, enabled)
+    self.assertIn(pre_upload._check_change_has_branch_field, disabled)
+
+    # Should be enabled if requested.
+    enabled, disabled = self.parse("""
+[Hook Overrides]
+branch_check: true
+""")
+    self.assertNotIn(pre_upload._check_change_has_no_branch_field, enabled)
+    self.assertIn(pre_upload._check_change_has_branch_field, enabled)
+    self.assertNotIn(pre_upload._check_change_has_branch_field, disabled)
+
+
 if __name__ == '__main__':
   cros_test_lib.main(module=__name__)