diff --git a/src/App/UserSelfManagementService.php b/src/App/UserSelfManagementService.php
index 177a8a52..dba210a8 100644
--- a/src/App/UserSelfManagementService.php
+++ b/src/App/UserSelfManagementService.php
@@ -307,6 +307,10 @@ final class UserSelfManagementService
      */
     private function isList(array $value): bool
     {
+        if ($value === []) {
+            return true;
+        }
+
         return array_keys($value) === range(0, count($value) - 1);
     }