diff --git a/lib/workers/pr/changelog/release-notes.js b/lib/workers/pr/changelog/release-notes.js
index d5f280eebc14623e88879a0f2da43269a48e17e1..b09fc5feba9c5358f274c46362fdf783454ee675 100644
--- a/lib/workers/pr/changelog/release-notes.js
+++ b/lib/workers/pr/changelog/release-notes.js
@@ -20,6 +20,10 @@ export {
 
 async function getReleaseList(githubApiBaseURL, repository) {
   logger.trace('getReleaseList()');
+  // istanbul ignore if
+  if (!githubApiBaseURL) {
+    return [];
+  }
   try {
     let url = githubApiBaseURL.replace(/\/?$/, '/');
     url += `repos/${repository}/releases?per_page=100`;