diff --git a/lib/index.js b/lib/index.js
index 9e9d5a57..ef5748e6 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -129,7 +129,7 @@ function base() {
       }
 
       if (options[0] === true) {
-        options[1] = undefined
+        options[0] = undefined
       }
 
       /** @type {Transformer|void} */