diff --git a/CHANGES.md b/CHANGES.md
index 19591b14..d8a752f2 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -39,23 +39,23 @@ D3 3.x was a monolithic library: the core functionality resided in a single [rep
 
 D3 4.0 is modular. Instead of one library, D3 is now [many small libraries](https://github.com/d3) that are designed to work together. You can pick and choose which parts to use as you see fit. Each library is maintained in a separate repository, allowing decentralized ownership and independent release cycles. Want to own a new repository in the [D3 organization](https://github.com/d3)? [Let me know!](https://twitter.com/mbostock)
 
-The [default bundle](https://d3js.org/d3.v4.0.0-alpha.49.js) of D3 4.0 conveniently aggregates [about thirty](https://github.com/d3/d3/blob/master/index.js) of these microlibraries.
+The [default bundle](https://d3js.org/d3.v4.0.0-alpha.50.js) of D3 4.0 conveniently aggregates [about thirty](https://github.com/d3/d3/blob/master/index.js) of these microlibraries.
 
 ```html
-<script src="https://d3js.org/d3.v4.0.0-alpha.49.min.js"></script>
+<script src="https://d3js.org/d3.v4.0.0-alpha.50.min.js"></script>
 ```
 
 As before, you can load optional plugins on top of the default bundle, such as [ColorBrewer scales](https://github.com/d3/d3-scale-chromatic):
 
 ```html
-<script src="https://d3js.org/d3.v4.0.0-alpha.49.min.js"></script>
+<script src="https://d3js.org/d3.v4.0.0-alpha.50.min.js"></script>
 <script src="https://d3js.org/d3-scale-chromatic.v0.3.min.js"></script>
 ```
 
 But now in 4.0, you don’t have to use the default bundle! Custom bundles are useful for applications that use a subset of D3’s features; for example, a React charting library might use D3’s scales and shapes, but use React instead of selections to manipulate the DOM. Or if you’re just using [d3-selection](https://github.com/d3/d3-selection), it’s only 5KB instead of 64KB for the default bundle. You can load D3 microlibraries using vanilla script tags or RequireJS (great for HTTP/2!):
 
 ```html
-<script src="https://d3js.org/d3-selection.v0.8.min.js"></script>
+<script src="https://d3js.org/d3-selection.v0.9.min.js"></script>
 ```
 
 You can `cat` D3 microlibraries into a custom bundle, or use tools such as [Webpack](https://webpack.github.io/) or [Rollup](http://rollupjs.org/) to create [optimized bundles](https://bl.ocks.org/mbostock/bb09af4c39c79cffcde4). The D3 microlibraries are written as [ES6 modules](http://www.2ality.com/2014/09/es6-modules-final.html), and Rollup lets you pick at the symbol level to produce the smallest bundles!
diff --git a/README.md b/README.md
index ee51c700..4b5637b0 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ For examples, [see the gallery](https://github.com/d3/d3/wiki/Gallery) and [mbos
 The master branch currently contains the prerelease of D3 4.0. The 4.0 API is not yet frozen and may change prior to the release. (For the latest stable release, 3.5.17, follow the [installation instructions](https://github.com/d3/d3/wiki#installing) on the wiki.) If you use NPM, `npm install d3@next`. Otherwise, download the [latest release](https://npmcdn.com/d3@next/build/). The released bundle supports AMD, CommonJS, and vanilla environments. Create a [custom bundle using Rollup](http://bl.ocks.org/mbostock/bb09af4c39c79cffcde4) or your preferred bundler. You can also load directly from [d3js.org](https://d3js.org):
 
 ```html
-<script src="https://d3js.org/d3.v4.0.0-alpha.49.min.js"></script>
+<script src="https://d3js.org/d3.v4.0.0-alpha.50.min.js"></script>
 ```
 
 For the non-minified version, remove `.min` from the file name.