diff --git a/src/apptask.js b/src/apptask.js
index 251d56088..e0d9bd6bf 100644
--- a/src/apptask.js
+++ b/src/apptask.js
@@ -768,7 +768,7 @@ function configure(app, args, progressCallback, callback) {
     assert.strictEqual(typeof progressCallback, 'function');
     assert.strictEqual(typeof callback, 'function');
 
-    const oldConfig = args.oldConfig;
+    const oldConfig = args.oldConfig || {}; // this can be null in repair cases
     const locationChanged = oldConfig.fqdn !== app.fqdn;
     const dataDirChanged = oldConfig.dataDir !== app.dataDir;