Actually force the download in S3

app/Helpers/StorageHelper.php

@@ -2,7 +2,6 @@
 
 namespace App\Helpers;
 
-use Illuminate\Contracts\Filesystem\FileNotFoundException;
 use Illuminate\Http\RedirectResponse;
 use Illuminate\Support\Facades\Storage;
 use Symfony\Component\HttpFoundation\BinaryFileResponse;
@@ -20,7 +19,14 @@ class StorageHelper
                 return response()->download(Storage::disk($disk)->path($filename)); // works for PRIVATE or public?!
 
             case 's3':
-                return redirect()->away(Storage::disk($disk)->temporaryUrl($filename, now()->addMinutes(5))); // works for private or public, I guess?
+                Storage::disk($disk)->temporaryUrl(
+                    $filename,
+                    now()->addMinutes(5),
+                    [
+                        'ResponseContentType' => 'application/octet-stream',
+                        'ResponseContentDisposition' => 'attachment; filename=download-file',
+                    ]
+                );
 
             default:
                 return Storage::disk($disk)->download($filename);
@@ -119,5 +125,4 @@ class StorageHelper
         return null;
 
     }
-
 }