diff --git a/webapp/tests/Unit/Controller/API/AccountBaseTestCase.php b/webapp/tests/Unit/Controller/API/AccountBaseTestCase.php
index 219de40fbd..c6cdd327a5 100644
--- a/webapp/tests/Unit/Controller/API/AccountBaseTestCase.php
+++ b/webapp/tests/Unit/Controller/API/AccountBaseTestCase.php
@@ -353,6 +353,6 @@ public function provideNewAccountFileNoPassword(): Generator
         $userData['type'] = 'admin';
         $userData['id'] = $userData['username'];
         yield [Yaml::dump([$userData], 1), 'yaml'];
-        yield [json_encode([$userData]), 'json'];
+        yield [json_encode([$userData], JSON_THROW_ON_ERROR), 'json'];
     }
 }