diff --git a/README.md b/README.md
index 152db52c..17304a7a 100644
--- a/README.md
+++ b/README.md
@@ -248,3 +248,4 @@ See the [guidelines for contributing][].
 [Visual Studio Express 2010]: http://www.microsoft.com/visualstudio/eng/products/visual-studio-2010-express
 [guidelines for contributing]: https://github.com/libuv/libuv/blob/master/CONTRIBUTING.md
 [libuv_banner]: https://raw.githubusercontent.com/libuv/libuv/master/img/banner.png
+[x32]: https://en.wikipedia.org/wiki/X32_ABI