diff --git a/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.test.ts b/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.test.ts
index 95ffe948a7..47aa0f0245 100644
--- a/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.test.ts
+++ b/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.test.ts
@@ -61,8 +61,9 @@ describe('WorkPackageResource service', () => {
       });
       $httpBackend.flush();
     };
-    const expectWpCacheUpdateWith = (...urls) => {
+    const testWpCacheUpdateWith = (prepare, ...urls) => {
       beforeEach(() => {
+        prepare();
         expectUncachedRequests(urls);
       });
 
@@ -91,21 +92,21 @@ describe('WorkPackageResource service', () => {
     });
 
     describe('when updating multiple linked resource', () => {
-      var linkNames = ['activities', 'attachments'];
-
-      beforeEach(() => {
-        workPackage.updateLinkedResources(...linkNames);
-      });
-
-      expectWpCacheUpdateWith(...linkNames);
+      testWpCacheUpdateWith(() => {
+        workPackage.updateLinkedResources('activities', 'attachments');
+      }, 'activities', 'attachments');
     });
 
     describe('when updating the activities', () => {
-      beforeEach(() => {
+      testWpCacheUpdateWith(() => {
         workPackage.updateActivities();
-      });
+      }, 'activities');
+    });
 
-      expectWpCacheUpdateWith('activities');
+    describe('when updating the attachments', () => {
+      testWpCacheUpdateWith(() => {
+        workPackage.updateAttachments();
+      }, 'activities', 'attachments');
     });
   });
 });
diff --git a/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.ts b/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.ts
index 1f216f69b6..36c6f2feb9 100644
--- a/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.ts
+++ b/frontend/app/components/api/api-v3/hal-resources/work-package-resource.service.ts
@@ -371,6 +371,14 @@ export class WorkPackageResource extends HalResource {
     this.updateLinkedResources('activities');
   }
 
+  /**
+   * Get updated attachments and activities from the server and inform the cache service
+   * about the update.
+   */
+  public updateAttachments() {
+    this.updateLinkedResources('activities', 'attachments');
+  }
+
   /**
    * Assign values from the form for a newly created work package resource.
    * @param form
diff --git a/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.test.ts b/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.test.ts
index 98edea97d9..473f3168b1 100644
--- a/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.test.ts
+++ b/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.test.ts
@@ -51,7 +51,8 @@ describe('wp-attachments.directive', () => {
       $unload: angular.noop,
       href: '/api/v3/work_packages/1/activities',
     },
-    updateLinkedResources: () => null
+    updateLinkedResources: () => null,
+    updateAttachments: () => null
   };
 
   beforeEach(angular.mock.module('openproject'));
diff --git a/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.ts b/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.ts
index 05867e9016..ac191664f6 100644
--- a/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.ts
+++ b/frontend/app/components/work-packages/wp-attachments/wp-attachments.directive.ts
@@ -110,7 +110,7 @@ export class WorkPackageAttachmentsController {
           // Reload the work package after attachments are uploaded to
           // provide the correct links, in e.g., the description
           this.wpCacheService.loadWorkPackage(<number> wp.id, true);
-        })
+        });
       });
   }
 
@@ -125,7 +125,7 @@ export class WorkPackageAttachmentsController {
     if (this.files.length > 0) {
       this.wpAttachments.upload(this.workPackage, this.files).then(() => {
         this.files = [];
-        this.attachmentsChanged();
+        this.workPackage.updateAttachments();
       });
     }
   };
@@ -146,7 +146,7 @@ export class WorkPackageAttachmentsController {
     if (!this.workPackage.isNew) {
       if (file._type === 'Attachment') {
         file.delete()
-          .then(() => this.attachmentsChanged())
+          .then(() => this.workPackage.updateAttachments())
           .catch(error => {
             this.wpNotificationsService.handleErrorResponse(error, this.workPackage);
           });
@@ -176,13 +176,6 @@ export class WorkPackageAttachmentsController {
     this.filterFiles(files);
     this.upload();
   }
-
-  /**
-   * Update the work package links affected by attachments: activities and attachments themselves
-   */
-  protected attachmentsChanged() {
-    this.workPackage.updateLinkedResources('attachments', 'activities');
-  }
 }
 
 function wpAttachmentsDirective():ng.IDirective {