diff --git a/app/Http/Controllers/AppController.php b/app/Http/Controllers/AppController.php
index 4da5b39ca6c8..8b33c71e93ef 100644
--- a/app/Http/Controllers/AppController.php
+++ b/app/Http/Controllers/AppController.php
@@ -85,7 +85,7 @@ class AppController extends BaseController
         $_ENV['APP_DEBUG'] = $app['debug'];
         $_ENV['APP_URL'] = $app['url'];
         $_ENV['APP_KEY'] = $app['key'];
-        $_ENV['APP_CIPHER'] = 'AES-256-CBC';
+        $_ENV['APP_CIPHER'] = env('APP_CIPHER', 'AES-256-CBC');
         $_ENV['DB_TYPE'] = $dbType;
         $_ENV['DB_HOST'] = $database['type']['host'];
         $_ENV['DB_DATABASE'] = $database['type']['database'];
@@ -278,6 +278,13 @@ class AppController extends BaseController
                 Artisan::call('db:seed', ['--force' => true, '--class' => 'UpdateSeeder']);
                 Event::fire(new UserSettingsChanged());
 
+                // legacy fix: check cipher is in .env file
+                if ( ! env('APP_CIPHER')) {
+                    $fp = fopen(base_path().'/.env', 'a');
+                    fwrite($fp, "\nAPP_CIPHER=rijndael-128");
+                    fclose($fp);
+                }
+
                 // show message with link to Trello board
                 $message = trans('texts.see_whats_new', ['version' => NINJA_VERSION]);
                 $message = link_to(RELEASES_URL, $message, ['target' => '_blank']);