diff --git a/src/apps.js b/src/apps.js
index 1e2b91788..ca1fb1aba 100644
--- a/src/apps.js
+++ b/src/apps.js
@@ -305,14 +305,6 @@ function validateRobotsTxt(robotsTxt) {
     return null;
 }
 
-function validateBackupFormat(format) {
-    assert.strictEqual(typeof format, 'string');
-
-    if (format === 'tgz' || format == 'rsync') return null;
-
-    return new AppsError(AppsError.BAD_FIELD, 'Invalid backup format');
-}
-
 function validateLabel(label) {
     if (label === null) return null;