diff --git a/frontend/src/app/components/api/op-file-upload/op-file-upload.service.ts b/frontend/src/app/components/api/op-file-upload/op-file-upload.service.ts
index 50c709eb63..db8bb3b2d4 100644
--- a/frontend/src/app/components/api/op-file-upload/op-file-upload.service.ts
+++ b/frontend/src/app/components/api/op-file-upload/op-file-upload.service.ts
@@ -29,7 +29,7 @@
 import {Injectable} from "@angular/core";
 import {HttpClient, HttpEvent, HttpEventType, HttpResponse} from "@angular/common/http";
 import {HalResource} from "core-app/modules/hal/resources/hal-resource";
-import {Observable} from "rxjs/Observable";
+import {Observable} from "rxjs";
 import {filter, map, share} from "rxjs/operators";
 import {HalResourceService} from "core-app/modules/hal/services/hal-resource.service";
 
diff --git a/frontend/src/app/components/resizer/main-menu-resizer.component.ts b/frontend/src/app/components/resizer/main-menu-resizer.component.ts
index ddb13f9c4d..d69645a39d 100644
--- a/frontend/src/app/components/resizer/main-menu-resizer.component.ts
+++ b/frontend/src/app/components/resizer/main-menu-resizer.component.ts
@@ -28,7 +28,7 @@
 
 import {ChangeDetectorRef, Component, ElementRef, HostListener, OnDestroy, OnInit} from '@angular/core';
 import {distinctUntilChanged} from 'rxjs/operators';
-import {Subscription} from 'rxjs/Subscription';
+import {Subscription} from 'rxjs';
 import {untilComponentDestroyed} from 'ng2-rx-componentdestroyed';
 import {MainMenuToggleService} from "core-components/resizer/main-menu-toggle.service";
 
diff --git a/frontend/src/app/components/resizer/main-menu-toggle.service.ts b/frontend/src/app/components/resizer/main-menu-toggle.service.ts
index 02ec660e9c..86ad86236c 100644
--- a/frontend/src/app/components/resizer/main-menu-toggle.service.ts
+++ b/frontend/src/app/components/resizer/main-menu-toggle.service.ts
@@ -27,7 +27,7 @@
 // ++
 
 import {Injectable} from '@angular/core';
-import {BehaviorSubject} from 'rxjs/BehaviorSubject';
+import {BehaviorSubject} from 'rxjs';
 import {I18nService} from "core-app/modules/common/i18n/i18n.service";
 
 @Injectable()
diff --git a/frontend/src/app/components/wp-fast-table/state/wp-table-focus.service.ts b/frontend/src/app/components/wp-fast-table/state/wp-table-focus.service.ts
index 3e8f1f3e3e..34ac772be4 100644
--- a/frontend/src/app/components/wp-fast-table/state/wp-table-focus.service.ts
+++ b/frontend/src/app/components/wp-fast-table/state/wp-table-focus.service.ts
@@ -1,10 +1,38 @@
-import {Observable} from 'rxjs/Observable';
-import {States} from '../../states.service';
-import {InputState} from 'reactivestates';
+//-- copyright
+// OpenProject is a project management system.
+// Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License version 3.
+//
+// OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+// Copyright (C) 2006-2013 Jean-Philippe Lang
+// Copyright (C) 2010-2013 the ChiliProject Team
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+//
+// See doc/COPYRIGHT.rdoc for more details.
+//++
+
+import {Injectable} from '@angular/core';
 import {WorkPackageTableSelection} from 'core-components/wp-fast-table/state/wp-table-selection.service';
 import {TableState} from 'core-components/wp-table/table-state/table-state';
-import {Injectable} from '@angular/core';
+import {InputState} from 'reactivestates';
+import {Observable} from 'rxjs';
 import {distinctUntilChanged, filter, map} from 'rxjs/operators';
+import {States} from '../../states.service';
 
 export interface WPFocusState {
   workPackageId:string;
diff --git a/frontend/src/app/components/wp-relations/wp-relations.component.ts b/frontend/src/app/components/wp-relations/wp-relations.component.ts
index 03b43903bb..5b438c6be9 100644
--- a/frontend/src/app/components/wp-relations/wp-relations.component.ts
+++ b/frontend/src/app/components/wp-relations/wp-relations.component.ts
@@ -26,18 +26,17 @@
 // See doc/COPYRIGHT.rdoc for more details.
 //++
 
-import {Observable} from 'rxjs/Observable';
-import {zip} from 'rxjs/observable/zip';
-import {take, takeUntil} from 'rxjs/operators';
+import {Component, Input, OnDestroy, OnInit} from '@angular/core';
+import {I18nService} from 'core-app/modules/common/i18n/i18n.service';
 import {RelationResource} from 'core-app/modules/hal/resources/relation-resource';
 import {WorkPackageResource} from 'core-app/modules/hal/resources/work-package-resource';
+
+import {componentDestroyed} from 'ng2-rx-componentdestroyed';
+import {Observable, zip} from 'rxjs';
+import {take, takeUntil} from 'rxjs/operators';
 import {WorkPackageCacheService} from '../work-packages/work-package-cache.service';
 import {RelatedWorkPackagesGroup} from './wp-relations.interfaces';
 import {RelationsStateValue, WorkPackageRelationsService} from './wp-relations.service';
-import {Component, Inject, Input, OnDestroy, OnInit} from "@angular/core";
-
-import {componentDestroyed} from "ng2-rx-componentdestroyed";
-import {I18nService} from "core-app/modules/common/i18n/i18n.service";
 
 
 @Component({
diff --git a/frontend/src/app/modules/common/focus/focus-within.directive.ts b/frontend/src/app/modules/common/focus/focus-within.directive.ts
index 16a2df08c2..78e959de1c 100644
--- a/frontend/src/app/modules/common/focus/focus-within.directive.ts
+++ b/frontend/src/app/modules/common/focus/focus-within.directive.ts
@@ -26,7 +26,7 @@
 // See doc/COPYRIGHT.rdoc for more details.
 //++
 
-import {BehaviorSubject} from 'rxjs/BehaviorSubject';
+import {BehaviorSubject} from 'rxjs';
 import {auditTime, takeUntil} from 'rxjs/operators';
 import {Directive, ElementRef, Input, OnDestroy, OnInit} from "@angular/core";
 import {componentDestroyed} from "ng2-rx-componentdestroyed";
diff --git a/frontend/src/app/modules/hal/services/hal-resource-sorting.service.ts b/frontend/src/app/modules/hal/services/hal-resource-sorting.service.ts
index cdd157805e..827efca495 100644
--- a/frontend/src/app/modules/hal/services/hal-resource-sorting.service.ts
+++ b/frontend/src/app/modules/hal/services/hal-resource-sorting.service.ts
@@ -26,16 +26,8 @@
 // See doc/COPYRIGHT.rdoc for more details.
 //++
 
-import {Injectable, Injector} from '@angular/core';
-import {HttpClient, HttpErrorResponse, HttpHeaders, HttpParams} from '@angular/common/http';
-import {catchError, map, tap} from 'rxjs/operators';
-import {Observable} from 'rxjs';
-import {HalResource, HalResourceClass} from 'core-app/modules/hal/resources/hal-resource';
-import {CollectionResource} from 'core-app/modules/hal/resources/collection-resource';
-import {HalLink, HalLinkInterface} from 'core-app/modules/hal/hal-link/hal-link';
-import {ErrorObservable} from 'rxjs/observable/ErrorObservable';
-import {initializeHalProperties} from 'core-app/modules/hal/helpers/hal-resource-builder';
-import {URLParamsEncoder} from 'core-app/modules/hal/services/url-params-encoder';
+import {Injectable} from '@angular/core';
+import {HalResource} from 'core-app/modules/hal/resources/hal-resource';
 
 @Injectable()
 export class HalResourceSortingService {