diff --git a/packages/openapi-code-generator/src/typescript/client/typescript-fetch/typescript-fetch-client-builder.ts b/packages/openapi-code-generator/src/typescript/client/typescript-fetch/typescript-fetch-client-builder.ts
index cd5a912b..7ed8b661 100644
--- a/packages/openapi-code-generator/src/typescript/client/typescript-fetch/typescript-fetch-client-builder.ts
+++ b/packages/openapi-code-generator/src/typescript/client/typescript-fetch/typescript-fetch-client-builder.ts
@@ -79,10 +79,15 @@ export class TypescriptFetchClientBuilder extends AbstractClientBuilder {
     const query = builder.query()
     const headers = builder.headers({nullContentTypeValue: "undefined"})
 
-    const returnType = builder
-      .returnType()
-      .map(({statusType, responseType}) => {
-        return `Res<${statusType},${responseType}>`
+    const builderReturnType = builder.returnType()
+    const nonDefaultStatusTypes = builderReturnType
+      .filter(({isDefault}) => !isDefault)
+      .map(({statusType}) => statusType)
+    const returnType = builderReturnType
+      .map(({statusType, responseType, isDefault}) => {
+        return isDefault ?
+          `Res<Exclude<StatusCode, ${nonDefaultStatusTypes.join(" | ")}>,${responseType}>` :
+          `Res<${statusType},${responseType}>`
       })
       .join(" | ")
 
diff --git a/packages/openapi-code-generator/src/typescript/server/typescript-koa/typescript-koa-router-builder.ts b/packages/openapi-code-generator/src/typescript/server/typescript-koa/typescript-koa-router-builder.ts
index f8ead11e..0dafe835 100644
--- a/packages/openapi-code-generator/src/typescript/server/typescript-koa/typescript-koa-router-builder.ts
+++ b/packages/openapi-code-generator/src/typescript/server/typescript-koa/typescript-koa-router-builder.ts
@@ -62,7 +62,7 @@ export class KoaRouterBuilder extends AbstractRouterBuilder {
       .add("KoaRuntimeError", "RequestInputType")
 
     this.imports.from("koa").addType("Next")
-    this.imports.from("@koa/router").addType("RouterContext").all("KoaRouter")
+    this.imports.from("@koa/router").addType("RouterContext").addType("RouterOptions").all("KoaRouter")
 
     const schemaBuilderType = this.schemaBuilder.type
 
@@ -258,8 +258,8 @@ ${this.operationTypes.flatMap((it) => it.statements).join("\n\n")}
 
 ${this.implementationExport(implementationExportName)}
 
-export function ${createRouterExportName}(implementation: ${implementationExportName}): KoaRouter {
-  const router = new KoaRouter()
+export function ${createRouterExportName}(implementation: ${implementationExportName}, options?: RouterOptions): KoaRouter {
+  const router = new KoaRouter(options)
 
   ${routerStatements.join("\n\n")}