diff --git a/src/SharethisManager.php b/src/SharethisManager.php
index 3032396..4923b12 100644
--- a/src/SharethisManager.php
+++ b/src/SharethisManager.php
@@ -256,6 +256,10 @@ class SharethisManager implements SharethisManagerInterface {
           $attributes['st_username'] = $data_options['twitter_recommends'];
         }
       }
+
+      // Alter to allow other module to change or add attribute elements.
+      \Drupal::moduleHandler()->alter('sharethis_attributes', $attributes);
+
       // Only show the display text if the type is set.
       if (!empty($type)) {
         $attributes['displayText'] = Html::escape($display);