diff --git a/CHANGELOG.md b/CHANGELOG.md
index 804cbb9..51ca8cb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 ## [unreleased]
 
+## [0.2.0]
+* Freeze objects returned by default. It doesn't actually make sense to return
+  unfrozen objects, as the original object could be mutated and it would
+  affect the new object. Object freezing is disabled if `NODE_ENV` is
+  `"production'`.
+* Update README with example for `reject`.
+
 ## [0.1.3]
 * Update README
 
@@ -14,7 +21,8 @@
 ## 0.1.0
 * Initial release
 
-[unreleased]: https://github.com/aaronjensen/updeep/compare/v0.1.3...HEAD
+[unreleased]: https://github.com/aaronjensen/updeep/compare/v0.2.0...HEAD
+[0.2.0]: https://github.com/aaronjensen/updeep/compare/v0.1.3...v0.2.0
 [0.1.3]: https://github.com/aaronjensen/updeep/compare/v0.1.2...v0.1.3
 [0.1.2]: https://github.com/aaronjensen/updeep/compare/v0.1.1...v0.1.2
 [0.1.1]: https://github.com/aaronjensen/updeep/compare/v0.1.0...v0.1.1
diff --git a/README.md b/README.md
index 45be631..a07e2e3 100644
--- a/README.md
+++ b/README.md
@@ -74,7 +74,7 @@ u({ x: { b: 3 }, y: { 1: 4 } }, { x: { a: 0, b: 0 }, y: [0, 0] });
 ### Use a function
 
 ```js
-var inc = function(i) { return i + 1; }
+function inc(i) { return i + 1; }
 u({ x: { b: inc } }, { x: { a: 0, b: 0 } });
 // => { x: { a: 0, b: 1 } }
 ```
@@ -94,6 +94,14 @@ u({ x: u.omit('b') }, { x: { a: 0, b: 0 } });
 // => { x: { a: 0 } }
 ```
 
+### Reject an item from an array
+
+```js
+function even(i) { return i % 2 === 0 };
+u({ x: u.reject(even) }, { x: [1, 2, 3, 4] });
+// => { x: [1, 3] }
+```
+
 ### With a default
 
 ```js
@@ -120,6 +128,11 @@ $ npm install --save updeep
 Requires [lodash] as a peer dependency, so make sure you have it installed as
 well.
 
+## Configuration
+
+If `NODE_ENV` is `"production"`, updeep will not attempt to freeze objects.
+This may yield a slight performance gain.
+
 ## Motivation
 
 While creating reducers for use with [redux], I wanted something that made it
@@ -128,6 +141,10 @@ advantages over things like [Immutable.js][immutablejs] such as debugging and
 destructuring. I wanted something more powerful than [icepick] and more
 composable than [React.addons.update].
 
+If you're manipulating massive amounts of data frequently, you may want to
+benchmark, as [Immutable.js][immutablejs] should be more efficient in that
+case.
+
 ## Contributing
 
 1. Fork it.