diff --git a/docs/docs/expression_language/why.ipynb b/docs/docs/expression_language/why.ipynb
index 3c0eaf0e57..9ee71c4e77 100644
--- a/docs/docs/expression_language/why.ipynb
+++ b/docs/docs/expression_language/why.ipynb
@@ -1007,7 +1007,7 @@
     "from langchain_openai import OpenAI\n",
     "from langchain_core.output_parsers import StrOutputParser\n",
     "from langchain_core.prompts import ChatPromptTemplate\n",
-    "from langchain_core.runnables import RunnablePassthrough\n",
+    "from langchain_core.runnables import RunnablePassthrough, ConfigurableField\n",
     "\n",
     "os.environ[\"LANGCHAIN_API_KEY\"] = \"...\"\n",
     "os.environ[\"LANGCHAIN_TRACING_V2\"] = \"true\"\n",