diff --git a/src/cli.js b/src/cli.js
index 3835136d2..2e49a63a9 100644
--- a/src/cli.js
+++ b/src/cli.js
@@ -422,7 +422,7 @@ async function build() {
     if (args['--purge']) {
       log.warn(['The `--purge` flag has been deprecated.', 'Please use `--content` instead.'])
       if (!args['--content']) {
-        args['--content'] = ['--purge']
+        args['--content'] = args['--purge']
       }
     }