diff --git a/src/Composer/Command/SelfUpdateCommand.php b/src/Composer/Command/SelfUpdateCommand.php
index 77cc9d69e..055f8af7f 100644
--- a/src/Composer/Command/SelfUpdateCommand.php
+++ b/src/Composer/Command/SelfUpdateCommand.php
@@ -231,7 +231,10 @@ TAGSPUBKEY
}
if (file_exists($backupFile)) {
- $io->writeError('Use composer self-update --rollback to return to version '.Composer::VERSION);
+ $io->writeError(sprintf(
+ 'Use composer self-update --rollback to return to version %s',
+ Composer::VERSION
+ ));
} else {
$io->writeError('A backup of the current version could not be written to '.$backupFile.', no rollback possible');
}