diff --git a/actions/shownotice.php b/actions/shownotice.php
index 005335e3b4..c5180568b3 100644
--- a/actions/shownotice.php
+++ b/actions/shownotice.php
@@ -303,7 +303,7 @@ class ShownoticeAction extends OwnerDesignAction
         $avatar = $this->profile->getAvatar(AVATAR_PROFILE_SIZE);
         $avatarUrl = ($avatar) ?
                      $avatar->displayUrl() :
-                     Avatar::defaultImage($avatar_size);
+                     Avatar::defaultImage(AVATAR_PROFILE_SIZE);
         $this->element('meta', array('property' => 'og:image',
                                      'content' => $avatarUrl));
         $this->element('meta', array('property' => 'og:description',