diff --git a/src/app/thumbnail/thumbnail.component.spec.ts b/src/app/thumbnail/thumbnail.component.spec.ts
index eea585f9f8..050df74713 100644
--- a/src/app/thumbnail/thumbnail.component.spec.ts
+++ b/src/app/thumbnail/thumbnail.component.spec.ts
@@ -49,7 +49,7 @@ describe('ThumbnailComponent', () => {
         comp.src = 'http://bit.stream';
         comp.defaultImage = 'http://default.img';
         comp.errorHandler();
-        comp.ngOnChanges();
+        comp.ngOnChanges({});
         fixture.detectChanges();
         const image: HTMLElement = de.query(By.css('img')).nativeElement;
         expect(image.getAttribute('alt')).toBe('TRANSLATED ' + comp.alt);
@@ -61,7 +61,7 @@ describe('ThumbnailComponent', () => {
         comp.errorHandler();
         expect(comp.src).toBe(null);
 
-        comp.ngOnChanges();
+        comp.ngOnChanges({});
         fixture.detectChanges();
         const placeholder = fixture.debugElement.query(By.css('div.thumbnail-placeholder')).nativeElement;
         expect(placeholder.innerHTML).toBe('TRANSLATED ' + comp.placeholder);
@@ -84,7 +84,7 @@ describe('ThumbnailComponent', () => {
 
     it('should display an image', () => {
       comp.thumbnail = thumbnail;
-      comp.ngOnChanges();
+      comp.ngOnChanges({});
       fixture.detectChanges();
       const image: HTMLElement = de.query(By.css('img')).nativeElement;
       expect(image.getAttribute('src')).toBe(comp.thumbnail._links.content.href);
@@ -92,7 +92,7 @@ describe('ThumbnailComponent', () => {
 
     it('should include the alt text', () => {
       comp.thumbnail = thumbnail;
-      comp.ngOnChanges();
+      comp.ngOnChanges({});
       fixture.detectChanges();
       const image: HTMLElement = de.query(By.css('img')).nativeElement;
       expect(image.getAttribute('alt')).toBe('TRANSLATED ' + comp.alt);
@@ -113,7 +113,7 @@ describe('ThumbnailComponent', () => {
 
       it('should show a loading animation', () => {
         comp.thumbnail = thumbnail;
-        comp.ngOnChanges();
+        comp.ngOnChanges({});
         fixture.detectChanges();
         expect(de.query(By.css('ds-loading'))).toBeTruthy();
       });
@@ -134,7 +134,7 @@ describe('ThumbnailComponent', () => {
 
       it('should display an image', () => {
         comp.thumbnail = thumbnail;
-        comp.ngOnChanges();
+        comp.ngOnChanges({});
         fixture.detectChanges();
         const image: HTMLElement = de.query(By.css('img')).nativeElement;
         expect(image.getAttribute('src')).toBe(comp.thumbnail.payload._links.content.href);
@@ -142,7 +142,7 @@ describe('ThumbnailComponent', () => {
 
       it('should display the alt text', () => {
         comp.thumbnail = thumbnail;
-        comp.ngOnChanges();
+        comp.ngOnChanges({});
         fixture.detectChanges();
         const image: HTMLElement = de.query(By.css('img')).nativeElement;
         expect(image.getAttribute('alt')).toBe('TRANSLATED ' + comp.alt);
diff --git a/src/app/thumbnail/thumbnail.component.ts b/src/app/thumbnail/thumbnail.component.ts
index 3e122cde78..90c48d19bc 100644
--- a/src/app/thumbnail/thumbnail.component.ts
+++ b/src/app/thumbnail/thumbnail.component.ts
@@ -1,4 +1,4 @@
-import { Component, Input, OnChanges } from '@angular/core';
+import { Component, Input, OnChanges, SimpleChanges } from '@angular/core';
 import { Bitstream } from '../core/shared/bitstream.model';
 import { hasValue } from '../shared/empty.util';
 import { RemoteData } from '../core/data/remote-data';
@@ -51,7 +51,7 @@ export class ThumbnailComponent implements OnChanges {
    * Resolve the thumbnail.
    * Use a default image if no actual image is available.
    */
-  ngOnChanges(): void {
+  ngOnChanges(changes: SimpleChanges): void {
     if (this.thumbnail === undefined || this.thumbnail === null) {
       return;
     }