diff --git a/h5p.classes.php b/h5p.classes.php
index ed9df9d..29de40f 100644
--- a/h5p.classes.php
+++ b/h5p.classes.php
@@ -3725,6 +3725,7 @@ class H5PCore {
       'cancelPublishConfirmationDialogDescription' => $this->h5pF->t('Are you sure you want to cancel the sharing process?'),
       'cancelPublishConfirmationDialogCancelButtonText' => $this->h5pF->t('No'),
       'cancelPublishConfirmationDialogConfirmButtonText' => $this->h5pF->t('Yes'),
+      'add': => $this->h5pF->t('Add')
     );
   }