diff --git a/vectordb_bench/backend/clients/alloydb/cli.py b/vectordb_bench/backend/clients/alloydb/cli.py
index aa3a5cbe..54d9b9fa 100644
--- a/vectordb_bench/backend/clients/alloydb/cli.py
+++ b/vectordb_bench/backend/clients/alloydb/cli.py
@@ -106,7 +106,7 @@ class AlloyDBScaNNTypedDict(AlloyDBTypedDict):
         int,
         click.option(
             "--max-num-levels",
-            type=click.Choice([1, 2]),
+            type=click.Choice(["1", "2"]),
             help="Maximum number of levels",
             default=1
         )