diff --git a/src/services/AuthenticationService.ts b/src/services/AuthenticationService.ts
index d01eec6..904c1cf 100644
--- a/src/services/AuthenticationService.ts
+++ b/src/services/AuthenticationService.ts
@@ -18,7 +18,6 @@
 /**
  * @file Auth service
  */
-import { isNullOrUndefined } from 'util';
 import { HttpHeaders } from '@angular/common/http';
 import { Injectable, Injector } from '@angular/core';
 import { Router } from '@angular/router';
@@ -28,6 +27,7 @@
 import { environment } from 'environment';
 import { BehaviorSubject, Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
+import { isNullOrUndefined } from 'SharedService';
 import { SharedService } from 'SharedService';
 import { ProjectModel } from '../models/VNFDModel';
 import { RestService } from './RestService';