diff --git a/__tests__/src/lib/MiradorViewer.test.js b/__tests__/src/lib/MiradorViewer.test.js
index 500ddff3b4979e7c7d272f05e994b132d220a7f2..11d7841ac4ca3d31d8595112663edbad184c8d7b 100644
--- a/__tests__/src/lib/MiradorViewer.test.js
+++ b/__tests__/src/lib/MiradorViewer.test.js
@@ -4,7 +4,6 @@ import MiradorViewer from '../../../src/lib/MiradorViewer';
 
 jest.unmock('react-i18next');
 jest.mock('react-dom');
-jest.mock('isomorphic-unfetch', () => jest.fn(() => Promise.resolve({ json: () => ({}) })));
 
 describe('MiradorViewer', () => {
   let container;
diff --git a/package.json b/package.json
index 84b34eb94d227b5c033448d1ecbb90ad1c22782d..95a97ce8232613f706fc3419903659d178407136 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,6 @@
     "dompurify": "^2.0.11",
     "i18next": "^19.5.0",
     "icomcom-react": "^1.0.1",
-    "isomorphic-unfetch": "^3.0.0",
     "jss": "^10.3.0",
     "jss-rtl": "^0.3.0",
     "lodash": "^4.17.11",