diff --git a/modules/openapi-generator/src/main/resources/typescript-rxjs/runtime.mustache b/modules/openapi-generator/src/main/resources/typescript-rxjs/runtime.mustache
index 366d9b5c441..97989df889a 100644
--- a/modules/openapi-generator/src/main/resources/typescript-rxjs/runtime.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-rxjs/runtime.mustache
@@ -35,7 +35,7 @@ export class Configuration {
     }
 
     get apiKey(): ((name: string) => string) | undefined {
-        const apiKey = this.configuration.apiKey;
+        const { apiKey } = this.configuration;
         if (!apiKey) {
             return undefined;
         }
@@ -43,7 +43,7 @@ export class Configuration {
     }
 
     get accessToken(): ((name: string, scopes?: string[]) => string) | undefined {
-        const accessToken = this.configuration.accessToken;
+        const { accessToken } = this.configuration;
         if (!accessToken) {
             return undefined;
         }
@@ -61,7 +61,7 @@ export class BaseAPI {
         this.middleware = configuration.middleware;
     }
 
-    withMiddleware = (middlewares: Middleware[]) => {
+    withMiddleware = (middlewares: Middleware[]): this => {
         const next = this.clone();
         next.middleware = next.middleware.concat(middlewares);
         return next;
@@ -121,7 +121,7 @@ export class BaseAPI {
      * Create a shallow clone of `this` by constructing a new instance
      * and then shallow cloning data members.
      */
-    private clone = (): BaseAPI =>
+    private clone = (): this =>
         Object.assign(Object.create(Object.getPrototypeOf(this)), this);
 }
 
diff --git a/samples/client/petstore/typescript-rxjs/builds/default/runtime.ts b/samples/client/petstore/typescript-rxjs/builds/default/runtime.ts
index e4c93e87e51..ad383a11642 100644
--- a/samples/client/petstore/typescript-rxjs/builds/default/runtime.ts
+++ b/samples/client/petstore/typescript-rxjs/builds/default/runtime.ts
@@ -46,7 +46,7 @@ export class Configuration {
     }
 
     get apiKey(): ((name: string) => string) | undefined {
-        const apiKey = this.configuration.apiKey;
+        const { apiKey } = this.configuration;
         if (!apiKey) {
             return undefined;
         }
@@ -54,7 +54,7 @@ export class Configuration {
     }
 
     get accessToken(): ((name: string, scopes?: string[]) => string) | undefined {
-        const accessToken = this.configuration.accessToken;
+        const { accessToken } = this.configuration;
         if (!accessToken) {
             return undefined;
         }
@@ -72,7 +72,7 @@ export class BaseAPI {
         this.middleware = configuration.middleware;
     }
 
-    withMiddleware = (middlewares: Middleware[]) => {
+    withMiddleware = (middlewares: Middleware[]): this => {
         const next = this.clone();
         next.middleware = next.middleware.concat(middlewares);
         return next;
@@ -132,7 +132,7 @@ export class BaseAPI {
      * Create a shallow clone of `this` by constructing a new instance
      * and then shallow cloning data members.
      */
-    private clone = (): BaseAPI =>
+    private clone = (): this =>
         Object.assign(Object.create(Object.getPrototypeOf(this)), this);
 }
 
diff --git a/samples/client/petstore/typescript-rxjs/builds/es6-target/runtime.ts b/samples/client/petstore/typescript-rxjs/builds/es6-target/runtime.ts
index e4c93e87e51..ad383a11642 100644
--- a/samples/client/petstore/typescript-rxjs/builds/es6-target/runtime.ts
+++ b/samples/client/petstore/typescript-rxjs/builds/es6-target/runtime.ts
@@ -46,7 +46,7 @@ export class Configuration {
     }
 
     get apiKey(): ((name: string) => string) | undefined {
-        const apiKey = this.configuration.apiKey;
+        const { apiKey } = this.configuration;
         if (!apiKey) {
             return undefined;
         }
@@ -54,7 +54,7 @@ export class Configuration {
     }
 
     get accessToken(): ((name: string, scopes?: string[]) => string) | undefined {
-        const accessToken = this.configuration.accessToken;
+        const { accessToken } = this.configuration;
         if (!accessToken) {
             return undefined;
         }
@@ -72,7 +72,7 @@ export class BaseAPI {
         this.middleware = configuration.middleware;
     }
 
-    withMiddleware = (middlewares: Middleware[]) => {
+    withMiddleware = (middlewares: Middleware[]): this => {
         const next = this.clone();
         next.middleware = next.middleware.concat(middlewares);
         return next;
@@ -132,7 +132,7 @@ export class BaseAPI {
      * Create a shallow clone of `this` by constructing a new instance
      * and then shallow cloning data members.
      */
-    private clone = (): BaseAPI =>
+    private clone = (): this =>
         Object.assign(Object.create(Object.getPrototypeOf(this)), this);
 }
 
diff --git a/samples/client/petstore/typescript-rxjs/builds/with-interfaces/runtime.ts b/samples/client/petstore/typescript-rxjs/builds/with-interfaces/runtime.ts
index e4c93e87e51..ad383a11642 100644
--- a/samples/client/petstore/typescript-rxjs/builds/with-interfaces/runtime.ts
+++ b/samples/client/petstore/typescript-rxjs/builds/with-interfaces/runtime.ts
@@ -46,7 +46,7 @@ export class Configuration {
     }
 
     get apiKey(): ((name: string) => string) | undefined {
-        const apiKey = this.configuration.apiKey;
+        const { apiKey } = this.configuration;
         if (!apiKey) {
             return undefined;
         }
@@ -54,7 +54,7 @@ export class Configuration {
     }
 
     get accessToken(): ((name: string, scopes?: string[]) => string) | undefined {
-        const accessToken = this.configuration.accessToken;
+        const { accessToken } = this.configuration;
         if (!accessToken) {
             return undefined;
         }
@@ -72,7 +72,7 @@ export class BaseAPI {
         this.middleware = configuration.middleware;
     }
 
-    withMiddleware = (middlewares: Middleware[]) => {
+    withMiddleware = (middlewares: Middleware[]): this => {
         const next = this.clone();
         next.middleware = next.middleware.concat(middlewares);
         return next;
@@ -132,7 +132,7 @@ export class BaseAPI {
      * Create a shallow clone of `this` by constructing a new instance
      * and then shallow cloning data members.
      */
-    private clone = (): BaseAPI =>
+    private clone = (): this =>
         Object.assign(Object.create(Object.getPrototypeOf(this)), this);
 }
 
diff --git a/samples/client/petstore/typescript-rxjs/builds/with-npm-version/runtime.ts b/samples/client/petstore/typescript-rxjs/builds/with-npm-version/runtime.ts
index e4c93e87e51..ad383a11642 100644
--- a/samples/client/petstore/typescript-rxjs/builds/with-npm-version/runtime.ts
+++ b/samples/client/petstore/typescript-rxjs/builds/with-npm-version/runtime.ts
@@ -46,7 +46,7 @@ export class Configuration {
     }
 
     get apiKey(): ((name: string) => string) | undefined {
-        const apiKey = this.configuration.apiKey;
+        const { apiKey } = this.configuration;
         if (!apiKey) {
             return undefined;
         }
@@ -54,7 +54,7 @@ export class Configuration {
     }
 
     get accessToken(): ((name: string, scopes?: string[]) => string) | undefined {
-        const accessToken = this.configuration.accessToken;
+        const { accessToken } = this.configuration;
         if (!accessToken) {
             return undefined;
         }
@@ -72,7 +72,7 @@ export class BaseAPI {
         this.middleware = configuration.middleware;
     }
 
-    withMiddleware = (middlewares: Middleware[]) => {
+    withMiddleware = (middlewares: Middleware[]): this => {
         const next = this.clone();
         next.middleware = next.middleware.concat(middlewares);
         return next;
@@ -132,7 +132,7 @@ export class BaseAPI {
      * Create a shallow clone of `this` by constructing a new instance
      * and then shallow cloning data members.
      */
-    private clone = (): BaseAPI =>
+    private clone = (): this =>
         Object.assign(Object.create(Object.getPrototypeOf(this)), this);
 }