diff --git a/app/controllers/course/members.php b/app/controllers/course/members.php
index 4e6afdc44f50552f63e661ab987161c1db172427..9a7f9c3a848d8454558ee6a595716643ac853664 100644
--- a/app/controllers/course/members.php
+++ b/app/controllers/course/members.php
@@ -564,7 +564,6 @@ class Course_MembersController extends AuthenticatedController
             $this->redirect(URLHelper::getURL('dispatch.php/messages/write', [
                 'default_subject' => $this->getSubject(),
                 'tmpsavesnd' => 1,
-                'course_id' => $this->course_id,
                 'emailrequest' => 1
             ]));
         } else {
diff --git a/app/controllers/messages.php b/app/controllers/messages.php
index 82d42d1cae5b1589a6e1aa63ce049dcb8c458f6a..f8871dd3dc0b57dcc91393f76fa02edee06fdf51 100644
--- a/app/controllers/messages.php
+++ b/app/controllers/messages.php
@@ -370,7 +370,7 @@ class MessagesController extends AuthenticatedController {
                     $query = "SELECT user_id, 'rec' AS snd_rec
                                       FROM seminar_user
                                       JOIN auth_user_md5 USING (user_id)
-                                      WHERE Seminar_id = ? AND seminar_user.visible != 'no'
+                                      WHERE Seminar_id = :course_id AND seminar_user.visible != 'no'
                                       ORDER BY Nachname, Vorname";
                 }
                 if ($query) {