diff --git a/libs/langchain-google-common/src/tests/chat_models.test.ts b/libs/langchain-google-common/src/tests/chat_models.test.ts
index dfd7de527e38..cb6674459c32 100644
--- a/libs/langchain-google-common/src/tests/chat_models.test.ts
+++ b/libs/langchain-google-common/src/tests/chat_models.test.ts
@@ -10,11 +10,14 @@ import {
   ToolMessage,
 } from "@langchain/core/messages";
 
+import { z } from "zod";
+import { zodToJsonSchema } from "zod-to-json-schema";
 import { ChatGoogleBase, ChatGoogleBaseInput } from "../chat_models.js";
 import { authOptions, MockClient, MockClientAuthInfo, mockId } from "./mock.js";
 import { GeminiTool, GoogleAIBaseLLMInput } from "../types.js";
 import { GoogleAbstractedClient } from "../auth.js";
 import { GoogleAISafetyError } from "../utils/safety.js";
+import { removeAdditionalProperties } from "../utils/zod_to_gemini_parameters.js";
 
 class ChatGoogle extends ChatGoogleBase<MockClientAuthInfo> {
   constructor(fields?: ChatGoogleBaseInput<MockClientAuthInfo>) {
@@ -840,3 +843,74 @@ describe("Mock ChatGoogle", () => {
     console.log(JSON.stringify(record?.opts?.data, null, 1));
   });
 });
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function extractKeys(obj: Record<string, any>, keys: string[] = []) {
+  for (const key in obj) {
+    if (Object.prototype.hasOwnProperty.call(obj, key)) {
+      keys.push(key);
+      if (typeof obj[key] === "object" && obj[key] !== null) {
+        extractKeys(obj[key], keys);
+      }
+    }
+  }
+  return keys;
+}
+
+test("removeAdditionalProperties can remove all instances of additionalProperties", async () => {
+  const idealResponseSchema = z.object({
+    idealResponse: z
+      .string()
+      .optional()
+      .describe("The ideal response to the question"),
+  });
+  const questionSchema = z.object({
+    question: z.string().describe("Question text"),
+    type: z.enum(["singleChoice", "multiChoice"]).describe("Question type"),
+    options: z.array(z.string()).describe("List of possible answers"),
+    correctAnswer: z
+      .string()
+      .optional()
+      .describe("correct answer from the possible answers"),
+    idealResponses: z
+      .array(idealResponseSchema)
+      .describe("Array of ideal responses to the question"),
+  });
+
+  const schema = z.object({
+    questions: z.array(questionSchema).describe("Array of question objects"),
+  });
+
+  const parsedSchemaArr = removeAdditionalProperties(zodToJsonSchema(schema));
+  const arrSchemaKeys = extractKeys(parsedSchemaArr);
+  expect(
+    arrSchemaKeys.find((key) => key === "additionalProperties")
+  ).toBeUndefined();
+  const parsedSchemaObj = removeAdditionalProperties(
+    zodToJsonSchema(questionSchema)
+  );
+  const arrSchemaObj = extractKeys(parsedSchemaObj);
+  expect(
+    arrSchemaObj.find((key) => key === "additionalProperties")
+  ).toBeUndefined();
+
+  const analysisSchema = z.object({
+    decision: z.enum(["UseAPI", "UseFallback"]),
+    explanation: z.string(),
+    apiDetails: z
+      .object({
+        serviceName: z.string(),
+        endpointName: z.string(),
+        parameters: z.record(z.unknown()),
+        extractionPath: z.string(),
+      })
+      .optional(),
+  });
+  const parsedAnalysisSchema = removeAdditionalProperties(
+    zodToJsonSchema(analysisSchema)
+  );
+  const analysisSchemaObj = extractKeys(parsedAnalysisSchema);
+  expect(
+    analysisSchemaObj.find((key) => key === "additionalProperties")
+  ).toBeUndefined();
+});
diff --git a/libs/langchain-google-common/src/utils/zod_to_gemini_parameters.ts b/libs/langchain-google-common/src/utils/zod_to_gemini_parameters.ts
index 229a578fbc21..101005e66bef 100644
--- a/libs/langchain-google-common/src/utils/zod_to_gemini_parameters.ts
+++ b/libs/langchain-google-common/src/utils/zod_to_gemini_parameters.ts
@@ -15,10 +15,7 @@ export function removeAdditionalProperties(
   if (typeof obj === "object" && obj !== null) {
     const newObj = { ...obj };
 
-    if (
-      "additionalProperties" in newObj &&
-      typeof newObj.additionalProperties === "boolean"
-    ) {
+    if ("additionalProperties" in newObj) {
       delete newObj.additionalProperties;
     }