diff --git a/aider/args.py b/aider/args.py
index 846c8ab05..f111b6dc0 100644
--- a/aider/args.py
+++ b/aider/args.py
@@ -119,7 +119,7 @@ def get_parser(default_config_files, git_root):
     )
     group.add_argument(
         "--thinking-tokens",
-        type=int,
+        type=str,
         help="Set the thinking token budget for models that support it (default: not set)",
     )
     group.add_argument(