diff --git a/.appveyor.yml b/.appveyor.yml
index 2ba95c228baf..c8ee04275c83 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -31,8 +31,10 @@ install:
     - rustup component remove rust-docs & exit 0
     - rustup update
     # Install "master" toolchain
-    - cargo install rustup-toolchain-install-master & exit 0
-    - rustup-toolchain-install-master -f -n master %RUSTC_HASH% -c cargo -c rust-src
+    - cargo install rustup-toolchain-install-master -f
+    # We need to install cargo here as well or else the DLL search path inside `cargo run`
+    # will be for the wrong toolchain. (On Unix, `./miri` takes care of this, but not here.)
+    - rustup-toolchain-install-master -f -n master %RUSTC_HASH% -c rust-src -c rustc-dev -c cargo
     - rustup default master
     - rustc --version
     - cargo --version
diff --git a/.travis.yml b/.travis.yml
index 51f02e76824b..e9df794b5940 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -38,8 +38,8 @@ before_script:
 - rustup component remove rust-docs || echo "rust-docs already gone"
 - rustup update
 # Install "master" toolchain
-- cargo install rustup-toolchain-install-master || echo "rustup-toolchain-install-master already installed"
-- travis_retry rustup-toolchain-install-master -f -n master $RUSTC_HASH -c rust-src
+- cargo install rustup-toolchain-install-master -f
+- travis_retry rustup-toolchain-install-master -f -n master $RUSTC_HASH -c rust-src -c rustc-dev
 - rustup default master
 - rustc --version
 - cargo --version
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 83e2338552e9..d6436873938e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -31,8 +31,10 @@ Miri heavily relies on internal rustc interfaces to execute MIR.  Still, some
 things (like adding support for a new intrinsic or a shim for an external
 function being called) can be done by working just on the Miri side.
 
-To prepare, make sure you are using a nightly Rust compiler.  Then you should be
-able to just `cargo build` Miri.
+To prepare, make sure you are using a nightly Rust compiler.  You also need to
+have the `rust-src` and `rustc-dev` components installed, which you can add via
+`rustup component add rust-src rustc-dev`.  Then you should be able to just
+`cargo build` Miri.
 
 In case this fails, your nightly might be incompatible with Miri master.  The
 `rust-version` file contains the commit hash of rustc that Miri is currently
@@ -41,7 +43,7 @@ to wait for the next nightly to get released. You can also use
 [`rustup-toolchain-install-master`](https://github.com/kennytm/rustup-toolchain-install-master)
 to install that exact version of rustc as a toolchain:
 ```
-rustup-toolchain-install-master $(cat rust-version) -c rust-src
+rustup-toolchain-install-master $(cat rust-version) -c rust-src -c rustc-dev
 ```
 
 Another common problem is outdated dependencies: Miri does not come with a
diff --git a/rust-version b/rust-version
index 543d4e269d41..61a6353bb4d9 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-55e00631e5bc5b16d40232914e57deeea197a8e4
+8e0007f829661e57d008d2e908c95f6e84b04b25