diff --git a/src/toolbox_langchain/async_tools.py b/src/toolbox_langchain/async_tools.py
index 998580d4..16b52ee0 100644
--- a/src/toolbox_langchain/async_tools.py
+++ b/src/toolbox_langchain/async_tools.py
@@ -42,7 +42,7 @@ class AsyncToolboxTool(BaseTool):
     def __init__(
         self,
         name: str,
-        schema: ToolSchema,
+        schema: Union[ToolSchema, dict],
         url: str,
         session: ClientSession,
         auth_tokens: dict[str, Callable[[], str]] = {},