diff --git a/frontend/app/components/api/api-v3/hal-resources/attachment-collection-resource.service.ts b/frontend/app/components/api/api-v3/hal-resources/attachment-collection-resource.service.ts
index 8a40c97d2c..23ba7fab23 100644
--- a/frontend/app/components/api/api-v3/hal-resources/attachment-collection-resource.service.ts
+++ b/frontend/app/components/api/api-v3/hal-resources/attachment-collection-resource.service.ts
@@ -31,7 +31,7 @@ import {CollectionResource} from './collection-resource.service';
 import {HalResource} from './hal-resource.service';
 import {
   OpenProjectFileUploadService,
-  UploadFile
+  UploadFile, UploadResult
 } from '../../op-file-upload/op-file-upload.service';
 import IPromise = angular.IPromise;
 
@@ -41,7 +41,7 @@ export class AttachmentCollectionResource extends CollectionResource {
   /**
    * Upload the given files to the $href property of this resource.
    */
-  public upload(files: UploadFile[]): IPromise<any> {
+  public upload(files: UploadFile[]): UploadResult {
     return opFileUpload.upload(this.$href, files);
   }
 }
diff --git a/frontend/app/components/api/op-file-upload/op-file-upload.service.test.ts b/frontend/app/components/api/op-file-upload/op-file-upload.service.test.ts
index e54f902f13..0a19b5edb0 100644
--- a/frontend/app/components/api/op-file-upload/op-file-upload.service.test.ts
+++ b/frontend/app/components/api/op-file-upload/op-file-upload.service.test.ts
@@ -80,8 +80,12 @@ describe('opFileUpload service', () => {
       }));
     });
 
-    it('should return a resolved promise', () => {
-      expect(result).to.eventually.be.fulfilled;
+    it('should return a result object that contains each upload in an array', () => {
+      expect(result.uploads).to.have.length(files.length);
+    });
+
+    it('should return a resolved promise that is the summary of the uploads', () => {
+      expect(result.upload).to.eventually.be.fulfilled;
     });
   });
 });
diff --git a/frontend/app/components/api/op-file-upload/op-file-upload.service.ts b/frontend/app/components/api/op-file-upload/op-file-upload.service.ts
index 5547d6e2e7..51c6758d8d 100644
--- a/frontend/app/components/api/op-file-upload/op-file-upload.service.ts
+++ b/frontend/app/components/api/op-file-upload/op-file-upload.service.ts
@@ -34,6 +34,11 @@ export interface UploadFile extends File {
   description: string;
 }
 
+export interface UploadResult {
+  uploads: IPromise<any>[];
+  upload: IPromise<any>;
+}
+
 export class OpenProjectFileUploadService {
   constructor(protected $q: IQService,
               protected Upload) {
@@ -42,8 +47,8 @@ export class OpenProjectFileUploadService {
   /**
    * Upload multiple files using `ngFileUpload` and return a single promise.
    */
-  public upload(url: string, files: UploadFile[]): IPromise<any> {
-    return this.$q.all(_.map(files, (file: UploadFile) => this.Upload.upload({
+  public upload(url: string, files: UploadFile[]): UploadResult {
+    const uploads = _.map(files, (file: UploadFile) => this.Upload.upload({
       file, url,
       fields: {
         metadata: {
@@ -51,7 +56,10 @@ export class OpenProjectFileUploadService {
           fileName: file.name,
         }
       }
-    })));
+    }));
+    const upload = this.$q.all(uploads);
+
+    return {uploads, upload};
   }
 }