diff --git a/src/backups.js b/src/backups.js
index ee028d639..454e7fb72 100644
--- a/src/backups.js
+++ b/src/backups.js
@@ -150,7 +150,7 @@ function getRestoreUrl(backupId, callback) {
 }
 
 function copyLastBackup(app, callback) {
-    assert(app && typeof app === 'object');
+    assert.strictEqual(typeof app, 'object');
     assert.strictEqual(typeof app.lastBackupId, 'string');
     assert.strictEqual(typeof callback, 'function');