diff --git a/kits/firestore-genai-chatbot/src/generative-client/genkit.ts b/kits/firestore-genai-chatbot/src/generative-client/genkit.ts
index cb68e1cfd..00a78e384 100644
--- a/kits/firestore-genai-chatbot/src/generative-client/genkit.ts
+++ b/kits/firestore-genai-chatbot/src/generative-client/genkit.ts
@@ -20,7 +20,6 @@ import {
   googleAI,
   vertexAI,
 } from "@genkit-ai/google-genai";
-import type { VertexPluginOptions } from "@genkit-ai/google-genai/lib/vertexai";
 import {
   type MessageData as ApiMessage,
   type GenerateOptions,
@@ -38,6 +37,9 @@ import {
   type Message,
 } from "./base_class";
 
+// @genkit-ai/google-genai does not re-export this type from its package root.
+type VertexPluginOptions = NonNullable<Parameters<typeof vertexAI>[0]>;
+
 genkitLogger.setLogLevel("info");
 
 /** Chat client backed by Genkit (the preferred path for single-candidate). */