diff --git a/openhands_cli/acp_impl/events/token_streamer.py b/openhands_cli/acp_impl/events/token_streamer.py
index 87c1d518..574abdc5 100644
--- a/openhands_cli/acp_impl/events/token_streamer.py
+++ b/openhands_cli/acp_impl/events/token_streamer.py
@@ -11,6 +11,7 @@
 from __future__ import annotations
 
 import asyncio
+from typing import Any
 
 from acp import (
     Client,
@@ -238,7 +239,7 @@ async def _send() -> None:
         else:
             self.loop.run_until_complete(_send())
 
-    def _handle_tool_call_streaming(self, tool_call) -> None:
+    def _handle_tool_call_streaming(self, tool_call: Any) -> None:
         if not tool_call:
             return
 
diff --git a/openhands_cli/acp_impl/test_utils.py b/openhands_cli/acp_impl/test_utils.py
index 35d85d6b..231c5819 100644
--- a/openhands_cli/acp_impl/test_utils.py
+++ b/openhands_cli/acp_impl/test_utils.py
@@ -21,7 +21,7 @@
 import select
 import subprocess
 import time
-from typing import Any
+from typing import IO, Any
 
 
 class UnbufferedJsonRpcReader:
@@ -31,7 +31,7 @@ class UnbufferedJsonRpcReader:
     that can cause messages to get stuck in buffers.
     """
 
-    def __init__(self, stdout) -> None:
+    def __init__(self, stdout: IO[bytes]) -> None:
         self.stdout = stdout
         self.buffer = b""
         self.fd = stdout.fileno()