diff --git a/extensions/approval/src/Listener/ApproveContent.php b/extensions/approval/src/Listener/ApproveContent.php
index fc7d963e5..240a4d9bd 100644
--- a/extensions/approval/src/Listener/ApproveContent.php
+++ b/extensions/approval/src/Listener/ApproveContent.php
@@ -17,7 +17,7 @@ class ApproveContent
     /**
      * @param Saving $event
      */
-    public function approvePost(Saving $event)
+    public static function approvePost(Saving $event)
     {
         $attributes = $event->data['attributes'];
         $post = $event->post;
@@ -40,7 +40,7 @@ class ApproveContent
     /**
      * @param PostWasApproved $event
      */
-    public function approveDiscussion(PostWasApproved $event)
+    public static function approveDiscussion(PostWasApproved $event)
     {
         $post = $event->post;
         $discussion = $post->discussion;
diff --git a/extensions/approval/src/Listener/UnapproveNewContent.php b/extensions/approval/src/Listener/UnapproveNewContent.php
index 09ed451fe..6251c7ab8 100644
--- a/extensions/approval/src/Listener/UnapproveNewContent.php
+++ b/extensions/approval/src/Listener/UnapproveNewContent.php
@@ -20,7 +20,7 @@ class UnapproveNewContent
     /**
      * @param Saving $event
      */
-    public function unapproveNewPosts(Saving $event)
+    public static function unapproveNewPosts(Saving $event)
     {
         $post = $event->post;
 
@@ -58,7 +58,7 @@ class UnapproveNewContent
      * @param GetModelIsPrivate $event
      * @return bool|null
      */
-    public function markUnapprovedContentAsPrivate(GetModelIsPrivate $event)
+    public static function markUnapprovedContentAsPrivate(GetModelIsPrivate $event)
     {
         if ($event->model instanceof Post || $event->model instanceof Discussion) {
             if (! $event->model->is_approved) {