diff --git a/lib/Controller/ImageController.php b/lib/Controller/ImageController.php
index dae6f8d3..77a28d73 100644
--- a/lib/Controller/ImageController.php
+++ b/lib/Controller/ImageController.php
@@ -76,15 +76,9 @@ class ImageController extends GenericApiController
      *
      * Get preview of many images
      */
-    public function multipreview(): Http\Response
+    public function multipreview(array $files): Http\Response
     {
-        return Util::guardExDirect(function (Http\IOutput $out) {
-            // read body to array
-            $body = file_get_contents('php://input');
-
-            /** @var array<array> */
-            $files = json_decode($body, true);
-
+        return Util::guardExDirect(function (Http\IOutput $out) use ($files) {
             // Filter files with valid parameters
             $files = array_filter($files, static function (array $file) {
                 return isset($file['reqid'], $file['fileid'], $file['x'], $file['y'], $file['a'])
diff --git a/src/components/frame/XImgWorker.ts b/src/components/frame/XImgWorker.ts
index b6bef576..9373a018 100644
--- a/src/components/frame/XImgWorker.ts
+++ b/src/components/frame/XImgWorker.ts
@@ -303,10 +303,8 @@ async function fetchOneImage(url: string) {
 async function fetchMultipreview(files: any[]) {
   return await fetch(config.multiUrl, {
     method: 'POST',
-    body: JSON.stringify(files),
-    headers: {
-      'Content-Type': 'application/json',
-    },
+    body: JSON.stringify({ files }),
+    headers: { 'Content-Type': 'application/json' },
   });
 }