diff --git a/webui/Dockerfile b/webui/Dockerfile
index 173ae423a..0a1cf28d4 100644
--- a/webui/Dockerfile
+++ b/webui/Dockerfile
@@ -12,3 +12,5 @@ RUN yarn install
 COPY . $WEBUI_DIR/
 
 EXPOSE 8080
+
+RUN yarn lint
diff --git a/webui/src/app/services/api.service.ts b/webui/src/app/services/api.service.ts
index 9f8fe00fb..6dc784e4f 100644
--- a/webui/src/app/services/api.service.ts
+++ b/webui/src/app/services/api.service.ts
@@ -1,14 +1,11 @@
 import { HttpClient, HttpErrorResponse, HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import 'rxjs/add/observable/empty';
 import 'rxjs/add/observable/of';
 import 'rxjs/add/operator/catch';
 import 'rxjs/add/operator/map';
 import 'rxjs/add/operator/retry';
 import { Observable } from 'rxjs/Observable';
-import { empty } from 'rxjs';
-import {catchError, retry} from "rxjs/internal/operators";
-
+import { EMPTY } from 'rxjs/internal/observable/empty';
 
 export interface ProviderType {
   [provider: string]: {
@@ -32,7 +29,7 @@ export class ApiService {
       .retry(4)
       .catch((err: HttpErrorResponse) => {
         console.error(`[version] returned code ${err.status}, body was: ${err.error}`);
-        return Observable.empty();
+        return EMPTY;
       });
   }
 
@@ -41,7 +38,7 @@ export class ApiService {
       .retry(2)
       .catch((err: HttpErrorResponse) => {
         console.error(`[health] returned code ${err.status}, body was: ${err.error}`);
-        return Observable.empty();
+        return EMPTY;
       });
   }