diff --git a/libs/langgraph/tests/test_pregel_async.py b/libs/langgraph/tests/test_pregel_async.py
index 4995addb6..f59433a07 100644
--- a/libs/langgraph/tests/test_pregel_async.py
+++ b/libs/langgraph/tests/test_pregel_async.py
@@ -21,6 +21,9 @@ from uuid import UUID
 
 import httpx
 import pytest
+from langchain_core.messages import (
+    ToolCall,
+)
 from langchain_core.runnables import (
     RunnableConfig,
     RunnableLambda,
@@ -3877,6 +3880,12 @@ async def test_prebuilt_tool_chat() -> None:
     ]
 
 
+# defined outside to allow deserializer to see it
+class ToolInput(BaseModel, arbitrary_types_allowed=True):
+    call: ToolCall
+    my_session: httpx.AsyncClient
+
+
 async def test_state_graph_packets() -> None:
     from langchain_core.language_models.fake_chat_models import (
         FakeMessagesListChatModel,
@@ -3885,7 +3894,6 @@ async def test_state_graph_packets() -> None:
         AIMessage,
         BaseMessage,
         HumanMessage,
-        ToolCall,
         ToolMessage,
     )
     from langchain_core.tools import tool
@@ -3941,19 +3949,15 @@ async def test_state_graph_packets() -> None:
         # Logic to decide whether to continue in the loop or exit
         if tool_calls := data["messages"][-1].tool_calls:
             return [
-                Send("tools", {"call": tool_call, "my_session": data["session"]})
+                Send("tools", ToolInput(call=tool_call, my_session=data["session"]))
                 for tool_call in tool_calls
             ]
         else:
             return END
 
-    class ToolInput(TypedDict):
-        call: ToolCall
-        my_session: httpx.Client
-
     async def tools_node(input: ToolInput, config: RunnableConfig) -> AgentState:
-        assert isinstance(input["my_session"], httpx.AsyncClient)
-        tool_call = input["call"]
+        assert isinstance(input.my_session, httpx.AsyncClient)
+        tool_call = input.call
         await asyncio.sleep(tool_call["args"].get("idx", 0) / 10)
         output = await tools_by_name[tool_call["name"]].ainvoke(
             tool_call["args"], config