diff --git a/lib/platform/github/index.js b/lib/platform/github/index.js
index b31bed0e294f9011c5b6adf9641bc3ab26421b37..ba1068bbce65f9fe6ae0bebe8997c8604aa2b3b2 100644
--- a/lib/platform/github/index.js
+++ b/lib/platform/github/index.js
@@ -219,6 +219,7 @@ async function initRepo({
     logger.debug('Parent sha is ' + parentSha);
     // This is a lovely "hack" by GitHub that lets us force update our fork's master
     // with the base commit from the parent repository
+    config.baseCommitSha = await getBaseCommitSHA();
     if (parentSha !== config.baseCommitSHA) {
       logger.info('Updating fork default branch');
       await get.patch(