diff --git a/docs/docs/how-tos/memory/add-summary-conversation-history.ipynb b/docs/docs/how-tos/memory/add-summary-conversation-history.ipynb
index 26a1ce61e..f2f374534 100644
--- a/docs/docs/how-tos/memory/add-summary-conversation-history.ipynb
+++ b/docs/docs/how-tos/memory/add-summary-conversation-history.ipynb
@@ -99,7 +99,7 @@
     "from typing import Literal\n",
     "\n",
     "from langchain_anthropic import ChatAnthropic\n",
-    "from langchain_core.messages import SystemMessage, RemoveMessage\n",
+    "from langchain_core.messages import SystemMessage, RemoveMessage, HumanMessage\n",
     "from langgraph.checkpoint.memory import MemorySaver\n",
     "from langgraph.graph import MessagesState, StateGraph, START, END\n",
     "\n",