diff --git a/lib/cronjobs/courseware.php b/lib/cronjobs/courseware.php
index 37259c6b309b00c72fdeb67b39ef641ab87fb614..d0eb491bd04cde9c83cbd1f00a0486880ee2f43f 100644
--- a/lib/cronjobs/courseware.php
+++ b/lib/cronjobs/courseware.php
@@ -223,6 +223,8 @@ class CoursewareCronjob extends CronJob
         $user = User::find($user_id);
         $course = Course::find($unit->range_id);
 
+        setTempLanguage('', $user->preferred_language);
+
         $template = $GLOBALS['template_factory']->open('courseware/mails/certificate');
         $html = $template->render(
             compact('user', 'course')
@@ -254,6 +256,8 @@ class CoursewareCronjob extends CronJob
 
         @unlink($filename);
 
+        restoreLanguage();
+
         // Add database entry for the certificate.
         if ($sent) {
             $cert = new Courseware\Certificate();
diff --git a/templates/courseware/mails/certificate.php b/templates/courseware/mails/certificate.php
index ed1e099de03a4665c0bdb6c4abbee4a8bf4d0c75..743db6f2bbf8f2d596b974bf5eec325a0140c867 100644
--- a/templates/courseware/mails/certificate.php
+++ b/templates/courseware/mails/certificate.php
@@ -14,7 +14,7 @@ switch($user->geschlecht) {
 }
 echo $p;
 printf(
-    _("Hiermit wird bescheinigt, dass %s am %s erfolgreich am Seminar %s teilgenommen hat."),
+    _("Hiermit wird bescheinigt, dass %1$s am %2$s erfolgreich am Seminar %3$s teilgenommen hat."),
     $span_bold . $anrede . ' ' . $user->getFullname() . $span_close,
     $span_bold . date('d.m.Y', time()) . $span_close,
     $span_bold . $course->name . $span_close