diff --git a/README.md b/README.md
index 31a74cea..a722eabd 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,6 @@ import * as CodeGenerator from "@himenon/openapi-typescript-code-generator";
 
 const main = () => {
   const params: CodeGenerator.Params = {
-    version: "v3",
     entryPoint: "your/openapi/spec.yml", // support .yml, .yaml, .json
   };
   const code = CodeGenerator.generateTypeScriptCode(params);
@@ -53,7 +52,6 @@ import * as CodeGenerator from "../lib";
 
 const main = () => {
   const params: CodeGenerator.Params = {
-    version: "v3",
     entryPoint: "your/openapi/spec.yml", // support .yml, .yaml, .json
     option: {
       makeApiClient: (context: ts.TransformationContext, codeGeneratorParamsList: CodeGenerator.Converter.v3.CodeGeneratorParams[]): ts.Statement[] => {
diff --git a/docs/ja/README-ja.md b/docs/ja/README-ja.md
index 862e4282..684b58f6 100644
--- a/docs/ja/README-ja.md
+++ b/docs/ja/README-ja.md
@@ -26,7 +26,6 @@ import * as CodeGenerator from "@himenon/openapi-typescript-code-generator";
 
 const main = () => {
   const params: CodeGenerator.Params = {
-    version: "v3",
     entryPoint: "your/openapi/spec.yml", // support .yml, .yaml, .json
   };
   const code = CodeGenerator.generateTypeScriptCode(params);
@@ -51,7 +50,6 @@ import * as CodeGenerator from "../lib";
 
 const main = () => {
   const params: CodeGenerator.Params = {
-    version: "v3",
     entryPoint: "your/openapi/spec.yml", // support .yml, .yaml, .json
     option: {
       makeApiClient: (context: ts.TransformationContext, codeGeneratorParamsList: CodeGenerator.Converter.v3.CodeGeneratorParams[]): ts.Statement[] => {