diff --git a/lib/Github/Api/Repository/Protection.php b/lib/Github/Api/Repository/Protection.php
index 73d1e6b5897..05dc39819b8 100644
--- a/lib/Github/Api/Repository/Protection.php
+++ b/lib/Github/Api/Repository/Protection.php
@@ -34,6 +34,9 @@ public function configure()
      */
     public function show($username, $repository, $branch)
     {
+        // Preview endpoint
+        $this->acceptHeaderValue = 'application/vnd.github.luke-cage-preview+json';
+
         return $this->get('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/branches/'.rawurlencode($branch).'/protection');
     }
 
@@ -51,6 +54,9 @@ public function show($username, $repository, $branch)
      */
     public function update($username, $repository, $branch, array $params = [])
     {
+        // Preview endpoint
+        $this->acceptHeaderValue = 'application/vnd.github.luke-cage-preview+json';
+
         return $this->put('/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/branches/'.rawurlencode($branch).'/protection', $params);
     }