diff --git a/lib/default.php b/lib/default.php
index 9c4c8cab05..71b2257cd5 100644
--- a/lib/default.php
+++ b/lib/default.php
@@ -310,7 +310,8 @@ $default =
                                  'TagSub' => null,
                                  'OpenID' => null,
                                  'Directory' => null,
-                                 'ExtendedProfile' => null),
+                                 'ExtendedProfile' => null,
+                                 'Activity' => null),
               'locale_path' => false, // Set to a path to use *instead of* each plugin's own locale subdirectories
               'server' => null,
               'sslserver' => null,