diff --git a/index.js b/index.js
index d11c8a3..027eef0 100644
--- a/index.js
+++ b/index.js
@@ -121,7 +121,7 @@ exports.build = function build(argv, callback) {
         pack = true;
         break;
       case 'O':
-        onto = option.optarg;
+        onto = option.optarg.replace(/[^\w]/gi, '');
         break;
       case 'c':
         commit = true;