diff --git a/doc/build.md b/doc/build.md
index e5693e663..18d620b4d 100644
--- a/doc/build.md
+++ b/doc/build.md
@@ -26,7 +26,7 @@ even better to send pull request if you can fix the problem.
 ## Contents
 - [Build the Shared Library](#build-the-shared-library)
   - [Building on Ubuntu/Debian](#building-on-ubuntu-debian)
-  - [Building on OSX](#building-on-osx)
+  - [Building on macOS](#building-on-macos)
   - [Building on Windows](#building-on-windows)
   - [Building with GPU support](#building-with-gpu-support)
   - [Windows Binaries](#windows-binaries)
@@ -57,7 +57,7 @@ git clone --recursive https://github.com/dmlc/xgboost
 cd xgboost; make -j4
 ```
 
-### Building on Mac OS X
+### Building on macOS
 
 **Install with pip - simple method**