diff --git a/config.toml.example b/config.toml.example
index f22f4a5a97579..bfd9e18cdd41a 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -138,6 +138,10 @@
 # specified, use this rustc binary instead as the stage0 snapshot compiler.
 #rustc = "/path/to/bin/rustc"
 
+# Instead of download the src/stage0.txt version of rustfmt specified,
+# use this rustfmt binary instead as the stage0 snapshot rustfmt.
+#rustfmt = "/path/to/bin/rustfmt"
+
 # Flag to specify whether any documentation is built. If false, rustdoc and
 # friends will still be compiled but they will not be used to generate any
 # documentation.
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index ed65a606ff525..944df66431fe8 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -203,6 +203,7 @@ struct Build {
     target: Vec<String>,
     cargo: Option<String>,
     rustc: Option<String>,
+    rustfmt: Option<String>, /* allow bootstrap.py to use rustfmt key */
     docs: Option<bool>,
     compiler_docs: Option<bool>,
     submodules: Option<bool>,