diff --git a/week6/day4.ipynb b/week6/day4.ipynb
index 56885b5..301fc27 100644
--- a/week6/day4.ipynb
+++ b/week6/day4.ipynb
@@ -350,7 +350,7 @@
     "    system_message = messages[0]['content']\n",
     "    messages = messages[1:]\n",
     "    response = claude.messages.create(\n",
-    "        model=\"claude-3-5-sonnet-20240620\",\n",
+    "        model=\"claude-sonnet-4-5-20250929\",\n",
     "        max_tokens=5,\n",
     "        system=system_message,\n",
     "        messages=messages\n",