diff --git a/README.md b/README.md
index 859e680..98ed546 100644
--- a/README.md
+++ b/README.md
@@ -43,8 +43,6 @@ dottie.set(values, 'some.nested.object', someValue, {
 });
 ```
 
-If you accept arbitrary/user-defined paths to `set` you should call `Object.preventExtensions(values)` first to guard against potential pollution.
-
 ### Transform object
 Transform object from keys with dottie notation to nested objects
 
diff --git a/dottie.js b/dottie.js
index d5aa55b..2fb9caf 100644
--- a/dottie.js
+++ b/dottie.js
@@ -130,7 +130,7 @@
       , piecesLength
       , piece
       , current
-      , transformed = {}
+      , transformed = Object.preventExtensions({})
       , key
       , keys = Object.keys(object)
       , length = keys.length