diff --git a/examples/rag/langgraph_agentic_rag.ipynb b/examples/rag/langgraph_agentic_rag.ipynb
index bde9d38e..5a812ec3 100644
--- a/examples/rag/langgraph_agentic_rag.ipynb
+++ b/examples/rag/langgraph_agentic_rag.ipynb
@@ -116,7 +116,7 @@
     "\n",
     "const GraphState = Annotation.Root({\n",
     "  messages: Annotation<BaseMessage[]>({\n",
-    "    value: (x, y) => x.concat(y),\n",
+    "    reducer: (x, y) => x.concat(y),\n",
     "    default: () => [],\n",
     "  })\n",
     "})"