diff --git a/cal/cal.php b/cal/cal.php
index 302549bb..f3823968 100644
--- a/cal/cal.php
+++ b/cal/cal.php
@@ -10,9 +10,13 @@
 
 function cal_install()
 {
+    register_hook('plugin_settings', 'addon/cal/cal.php', 'cal_addon_settings');
+    register_hook('plugin_settings_post', 'addon/cal/cal.php', 'cal_addon_settings_post');
 }
 function cal_uninstall()
 {
+    unregister_hook('plugin_settings', 'addon/cal/cal.php', 'cal_addon_settings');
+    unregister_hook('plugin_settings_post', 'addon/cal/cal.php', 'cal_addon_settings_post');
 }
 function cal_module()
 {
@@ -37,4 +41,15 @@ function cal_content()
     return $o;
 }
 
+function cal_addon_settings_post ( &$a, &$b  )
+{
+    if (! local_user())
+	return;
+}
+function cal_addon_settings ( &$a, &$s  )
+{
+    if (! local_user())
+	return;
+}
+
 ?>