diff --git a/lib/workers/pr/changelog.js b/lib/workers/pr/changelog.js
index 988666c3fa..24b2337af0 100644
--- a/lib/workers/pr/changelog.js
+++ b/lib/workers/pr/changelog.js
@@ -17,8 +17,9 @@ async function getChangeLogJSON(depName, fromVersion, newVersion, logger) {
     return await changelog.generate(depName, semverString);
   } catch (err) {
     if (
-      err.message.indexOf('did not specify the repository url') !== -1 ||
-      err.message.indexOf('Unknown Github Repo') !== -1
+      err.message &&
+      (err.message.indexOf('did not specify the repository url') !== -1 ||
+        err.message.indexOf('Unknown Github Repo') !== -1)
     ) {
       logger.debug({ err }, `getChangeLogJSON error`);
     } else {