diff --git a/README.md b/README.md
index aa8e0315b76..aa89df9731f 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,28 @@ Then, inside your own project, use `cargo +nightly miri` to run your project, if
 a bin project, or run `cargo +nightly miri test` to run all tests in your project
 through miri.
 
+## Running miri with full libstd
+
+Per default libstd does not contain the MIR of non-polymorphic functions.  When
+miri hits a call to such a function, execution terminates.  To fix this, it is
+possible to compile libstd with full MIR:
+
+```sh
+cargo install xargo
+cd xargo/
+RUSTFLAGS='-Zalways-encode-mir' xargo build --target `rustc -vV | egrep '^host: ' | sed 's/^host: //'`
+```
+
+Now you can run miri against the libstd compiled by xargo:
+
+```sh
+cargo run --bin miri -- --sysroot ~/.xargo/HOST tests/run-pass/vecs.rs
+```
+
+Notice that you will have to re-run the last step of the preparations above when
+your toolchain changes (e.g., when you update the nightly).  Also, xargo doesn't
+currently work with nightlies newer than 2017-04-23.
+
 ## Contributing and getting help
 
 Check out the issues on this GitHub repository for some ideas. There's lots that
diff --git a/xargo/Cargo.lock b/xargo/Cargo.lock
new file mode 100644
index 00000000000..031ad9a8795
--- /dev/null
+++ b/xargo/Cargo.lock
@@ -0,0 +1,4 @@
+[root]
+name = "miri-xargo"
+version = "0.0.0"
+
diff --git a/xargo/Cargo.toml b/xargo/Cargo.toml
new file mode 100644
index 00000000000..9129c105b11
--- /dev/null
+++ b/xargo/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "miri-xargo"
+description = "A dummy project for building libstd with xargo."
+version = "0.0.0"
+
+[dependencies]
diff --git a/xargo/Xargo.toml b/xargo/Xargo.toml
new file mode 100644
index 00000000000..32f45c4a981
--- /dev/null
+++ b/xargo/Xargo.toml
@@ -0,0 +1,2 @@
+[dependencies]
+std = {features = ["panic_unwind", "jemalloc"]}
diff --git a/xargo/src/lib.rs b/xargo/src/lib.rs
new file mode 100644
index 00000000000..e69de29bb2d