diff --git a/lib/workers/repository/process/lookup/index.spec.ts b/lib/workers/repository/process/lookup/index.spec.ts
index 3d1be00a412ba8..a4829cf3ba19f6 100644
--- a/lib/workers/repository/process/lookup/index.spec.ts
+++ b/lib/workers/repository/process/lookup/index.spec.ts
@@ -28,7 +28,8 @@ jest.mock('../../../../datasource/git-submodules');
 
 qJson.latestVersion = '1.4.1';
 
-const docker = mocked(datasourceDocker);
+const docker = mocked(datasourceDocker) as any;
+docker.defaultRegistryUrls = ['https://index.docker.io'];
 const gitSubmodules = mocked(datasourceGitSubmodules);
 
 let config: lookup.LookupUpdateConfig;