diff --git a/README.md b/README.md
index 3399f7fe6c8..fe9776bc5f8 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,7 @@ by running `./x.py --help` or reading the [rustc dev guide][rustcguidebuild].
    * `python` 3 or 2.7
    * GNU `make` 3.81 or later
    * `cmake` 3.4.3 or later
+   * `ninja`
    * `curl`
    * `git`
    * `ssl` which comes in `libssl-dev` or `openssl-devel`
diff --git a/config.toml.example b/config.toml.example
index 36587cc0784..9abb8add785 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -49,10 +49,8 @@
 # dynamic version to be available.
 #static-libstdcpp = false
 
-# Tell the LLVM build system to use Ninja instead of the platform default for
-# the generated build system. This can sometimes be faster than make, for
-# example.
-#ninja = false
+# Whether to use Ninja to build LLVM. This runs much faster than make.
+#ninja = true
 
 # LLVM targets to build support for.
 # Note: this is NOT related to Rust compilation targets. However, as Rust is
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 8b8b01b1153..f549de6570f 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -450,6 +450,7 @@ fn normalize_python_path(path: OsString) -> PathBuf {
     pub fn default_opts() -> Config {
         let mut config = Config::default();
         config.llvm_optimize = true;
+        config.ninja = true;
         config.llvm_version_check = true;
         config.backtrace = true;
         config.rust_optimize = true;