diff --git a/examples/chatbots/customer_support_small_model.ipynb b/examples/chatbots/customer_support_small_model.ipynb
index af492e193..e4cf44ed4 100644
--- a/examples/chatbots/customer_support_small_model.ipynb
+++ b/examples/chatbots/customer_support_small_model.ipynb
@@ -215,7 +215,7 @@
     "  let trimmedHistory = state.messages;\n",
     "  // Make the user's question the most recent message in the history.\n",
     "  // This helps small models stay focused.\n",
-    "  if (trimmedHistory.at(-1)._getType() === \"ai\") {\n",
+    "  if (trimmedHistory[trimmedHistory.length - 1].getType() === \"ai\") {\n",
     "    trimmedHistory = trimmedHistory.slice(0, -1);\n",
     "  }\n",
     "\n",
@@ -275,7 +275,7 @@
     "  let trimmedHistory = state.messages;\n",
     "  // Make the user's question the most recent message in the history.\n",
     "  // This helps small models stay focused.\n",
-    "  if (trimmedHistory.at(-1)._getType() === \"ai\") {\n",
+    "  if (trimmedHistory[trimmedHistory.length - 1].getType() === \"ai\") {\n",
     "    trimmedHistory = trimmedHistory.slice(0, -1);\n",
     "  }\n",
     "\n",
@@ -423,7 +423,7 @@
    "source": [
     "builder = builder\n",
     "  .addEdge(\"technical_support\", \"__end__\")\n",
-    "  .addConditionalEdges(\"billing_support\", async (state) => {\n",
+    "  .addConditionalEdges(\"billing_support\", async (state: typeof StateAnnotation.State) => {\n",
     "    if (state.nextRepresentative.includes(\"REFUND\")) {\n",
     "      return \"refund\";\n",
     "    } else {\n",