diff --git a/lib/std.js b/lib/std.js
index d40ba49..22599c2 100644
--- a/lib/std.js
+++ b/lib/std.js
@@ -182,7 +182,7 @@ function rotate(target, callback, onError) {
         }
 
         i++;
-        i = i % keywords.length;
+        i = i % target.length;
     }
 };