diff --git a/src/apps/apiApp/backend/ApiApp.ts b/src/apps/apiApp/backend/ApiApp.ts
index f0a2ec6..af90271 100644
--- a/src/apps/apiApp/backend/ApiApp.ts
+++ b/src/apps/apiApp/backend/ApiApp.ts
@@ -4,7 +4,7 @@ export class ApiApp {
   server?: Server;
 
   async start() {
-    const port: string = process.env.PORT || '3000';
+    const port: string = process.env.PORT ?? '3000';
     this.server = new Server(port);
 
     return this.server.listen();
diff --git a/src/apps/apiApp/backend/dependency-injection/index.ts b/src/apps/apiApp/backend/dependency-injection/index.ts
index e1dcaa5..ab88262 100644
--- a/src/apps/apiApp/backend/dependency-injection/index.ts
+++ b/src/apps/apiApp/backend/dependency-injection/index.ts
@@ -2,7 +2,7 @@ import { ContainerBuilder, YamlFileLoader } from 'node-dependency-injection';
 
 const container = new ContainerBuilder();
 const loader = new YamlFileLoader(container);
-const env = process.env.NODE_ENV || 'dev';
+const env = process.env.NODE_ENV ?? 'dev';
 
 loader.load(`${__dirname}/application_${env}.yml`);