diff --git a/apps/theming/lib/Jobs/MigrateBackgroundImages.php b/apps/theming/lib/Jobs/MigrateBackgroundImages.php
index 54c0d591e4049..39731ef556fae 100644
--- a/apps/theming/lib/Jobs/MigrateBackgroundImages.php
+++ b/apps/theming/lib/Jobs/MigrateBackgroundImages.php
@@ -69,9 +69,8 @@ public function __construct(
 	}
 
 	protected function run($argument): void {
-		if (!isset($argument['stage'])) {
-			// not executed in 25.0.0?!
-			$argument['stage'] = self::STAGE_PREPARE;
+		if (!is_array($argument) || !isset($argument['stage'])) {
+			throw new \Exception('Job '.self::class.' called with wrong argument');
 		}
 
 		switch ($argument['stage']) {
@@ -99,10 +98,10 @@ protected function runPreparation(): void {
 			$userIds = $result->fetchAll(\PDO::FETCH_COLUMN);
 			$this->storeUserIdsToProcess($userIds);
 		} catch (\Throwable $t) {
-			$this->jobList->add(self::class, self::STAGE_PREPARE);
+			$this->jobList->add(self::class, ['stage' => self::STAGE_PREPARE]);
 			throw $t;
 		}
-		$this->jobList->add(self::class, self::STAGE_EXECUTE);
+		$this->jobList->add(self::class, ['stage' => self::STAGE_EXECUTE]);
 	}
 
 	/**