diff --git a/scripts/lib/managed-extensions.py b/scripts/lib/managed-extensions.py
index ba3a338..df2f3fa 100644
--- a/scripts/lib/managed-extensions.py
+++ b/scripts/lib/managed-extensions.py
@@ -344,10 +344,11 @@ class Manager:
         if not re.fullmatch(r'[a-z0-9@/_.-]+', package):
             raise ValueError('Invalid CLI package.')
         record = next((r for r in self.state['resources'] if r['client'] == client and r['name'] == entry['name']), None)
-        if record is not None:
+        installed = shutil.which(package) is not None
+        if record is not None and installed and not self.update:
             return
-        self.command(['npm', 'install', '--global', package])
-        if not self.dry_run:
+        self.command(['npm', 'update' if record is not None and installed else 'install', '--global', package])
+        if not self.dry_run and record is None:
             self.state['resources'].append(dict(client=client, name=entry['name'], kind='cli', package=package))
             self.save()
 
diff --git a/scripts/tests/test-managed-extensions.py b/scripts/tests/test-managed-extensions.py
index e34b90b..2194a8d 100644
--- a/scripts/tests/test-managed-extensions.py
+++ b/scripts/tests/test-managed-extensions.py
@@ -272,6 +272,20 @@ class ManagedExtensionTests(unittest.TestCase):
         self.assertIn(['claude', 'plugin', 'install', 'qmd@qmd', '--scope', 'user'], self.commands)
         self.assertNotIn(['codex', 'mcp', 'add', 'qmd', '--', 'qmd', 'mcp'], self.commands)
 
+    def test_managed_mcporter_updates_when_requested(self):
+        self.manager().sync([mcporter()], ['codex'], {'MCPorter'})
+        self.commands.clear()
+        with patch.object(extensions.shutil, 'which', return_value='mcporter'):
+            self.manager(update=True).sync([mcporter()], ['codex'], {'MCPorter'})
+        self.assertEqual([['npm', 'update', '--global', 'mcporter']], self.commands)
+
+    def test_managed_mcporter_reinstalls_when_command_is_missing(self):
+        self.manager().sync([mcporter()], ['codex'], {'MCPorter'})
+        self.commands.clear()
+        with patch.object(extensions.shutil, 'which', return_value=None):
+            self.manager().sync([mcporter()], ['codex'], {'MCPorter'})
+        self.assertEqual([['npm', 'install', '--global', 'mcporter']], self.commands)
+
     def test_mcporter_replaces_direct_context7_plugin(self):
         self.manager().sync([mcp(), mcporter()], ['codex'], {'Context7', 'MCPorter'})
         config = str(self.home / '.mcporter/mcporter.json')