diff --git a/cargo-nightly-build b/cargo-nightly-build
new file mode 100644
index 00000000000..a8889e980b0
--- /dev/null
+++ b/cargo-nightly-build
@@ -0,0 +1 @@
+2014-10-21
diff --git a/etc/ci/travis.script.sh b/etc/ci/travis.script.sh
index b2b286cd490..e8eaafe34c6 100755
--- a/etc/ci/travis.script.sh
+++ b/etc/ci/travis.script.sh
@@ -37,7 +37,7 @@ for t in "${tasks[@]}"; do
             if [ "${TRAVIS_BRANCH}" = "master" ] && [ "${TRAVIS_PULL_REQUEST}" = "false" ]
             then
                 mkdir -p target/doc
-                cp -R rust/doc/* target/doc/
+                cp -R ~/.servo/rust/$(cat rust-snapshot-hash)*/doc/* target/doc/
                 cp etc/doc.servo.org/* target/doc/
                 ./mach doc  # After copying rust/doc, so that the crate index is correct.
                 sudo pip install ghp-import
diff --git a/python/servo/bootstrap_commands.py b/python/servo/bootstrap_commands.py
index b92198aae3c..1a1d95adde0 100644
--- a/python/servo/bootstrap_commands.py
+++ b/python/servo/bootstrap_commands.py
@@ -78,7 +78,7 @@ class MachCommands(CommandBase):
                      help='Force download even if a snapshot already exists')
     def bootstrap_rustc(self, force=False):
         rust_dir = path.join(
-            self.context.topdir, "rust", *self.rust_snapshot_path().split("/"))
+            self.context.sharedir, "rust", *self.rust_snapshot_path().split("/"))
         if not force and path.exists(path.join(rust_dir, "bin", "rustc")):
             print("Snapshot Rust compiler already downloaded.", end=" ")
             print("Use |bootstrap_rust --force| to download again.")
@@ -107,7 +107,8 @@ class MachCommands(CommandBase):
                      action='store_true',
                      help='Force download even if cargo already exists')
     def bootstrap_cargo(self, force=False):
-        cargo_dir = path.join(self.context.topdir, "cargo")
+        cargo_dir = path.join(self.context.sharedir, "cargo",
+                              self.cargo_build_id())
         if not force and path.exists(path.join(cargo_dir, "bin", "cargo")):
             print("Cargo already downloaded.", end=" ")
             print("Use |bootstrap_cargo --force| to download again.")
@@ -115,11 +116,12 @@ class MachCommands(CommandBase):
 
         if path.isdir(cargo_dir):
             shutil.rmtree(cargo_dir)
-        os.mkdir(cargo_dir)
+        os.makedirs(cargo_dir)
 
         tgz_file = "cargo-nightly-%s.tar.gz" % host_triple()
         # FIXME(#3582): use https.
-        nightly_url = "http://static.rust-lang.org/cargo-dist/2014-10-21/%s" % tgz_file
+        nightly_url = "http://static.rust-lang.org/cargo-dist/%s/%s" % \
+            (self.cargo_build_id(), tgz_file)
 
         download("Cargo nightly", nightly_url, tgz_file)
 
diff --git a/python/servo/command_base.py b/python/servo/command_base.py
index 72810efff0d..d78c0e13a1c 100644
--- a/python/servo/command_base.py
+++ b/python/servo/command_base.py
@@ -54,6 +54,9 @@ class CommandBase(object):
         if not hasattr(self.context, "bootstrapped"):
             self.context.bootstrapped = False
 
+        if not hasattr(self.context, "sharedir"):
+            self.context.sharedir = path.join(path.expanduser("~/"), ".servo")
+
         config_path = path.join(context.topdir, ".servobuild")
         if path.exists(config_path):
             self.config = toml.loads(open(config_path).read())
@@ -68,10 +71,10 @@ class CommandBase(object):
         self.config["tools"].setdefault("cargo-root", "")
         if not self.config["tools"]["system-rust"]:
             self.config["tools"]["rust-root"] = path.join(
-                context.topdir, "rust", *self.rust_snapshot_path().split("/"))
+                context.sharedir, "rust", *self.rust_snapshot_path().split("/"))
         if not self.config["tools"]["system-cargo"]:
             self.config["tools"]["cargo-root"] = path.join(
-                context.topdir, "cargo")
+                context.sharedir, "cargo", self.cargo_build_id())
 
         self.config.setdefault("build", {})
         self.config["build"].setdefault("android", False)
@@ -82,6 +85,7 @@ class CommandBase(object):
         self.config["android"].setdefault("toolchain", "")
 
     _rust_snapshot_path = None
+    _cargo_build_id = None
 
     def rust_snapshot_path(self):
         if self._rust_snapshot_path is None:
@@ -90,6 +94,12 @@ class CommandBase(object):
             self._rust_snapshot_path = "%s-%s" % (snapshot_hash, host_triple())
         return self._rust_snapshot_path
 
+    def cargo_build_id(self):
+        if self._cargo_build_id is None:
+            filename = path.join(self.context.topdir, "cargo-nightly-build")
+            self._cargo_build_id = open(filename).read().strip()
+        return self._cargo_build_id
+
     def build_env(self):
         """Return an extended environment dictionary."""
         env = os.environ.copy()
@@ -148,7 +158,7 @@ class CommandBase(object):
             Registrar.dispatch("bootstrap-rust", context=self.context)
         if not self.config["tools"]["system-cargo"] and \
            not path.exists(path.join(
-                self.context.topdir, "cargo", "bin", "cargo")):
+                self.config["tools"]["cargo-root"], "bin", "cargo")):
             Registrar.dispatch("bootstrap-cargo", context=self.context)
 
         self.context.bootstrapped = True