--- a/python/mozboot/mozboot/base.py
+++ b/python/mozboot/mozboot/base.py
@@ -254,32 +254,29 @@ class BaseBootstrapper(object):
     def ensure_stylo_packages(self, state_dir, checkout_root):
         '''
         Install any necessary packages needed for Stylo development.
         '''
         raise NotImplementedError(
             '%s does not yet implement ensure_stylo_packages()'
             % __name__)
 
-    def install_tooltool_clang_package(self, state_dir, checkout_root, manifest_file):
-        abs_manifest_file = os.path.join(checkout_root, manifest_file)
-
+    def install_tooltool_clang_package(self, state_dir, checkout_root, toolchain_job):
         mach_binary = os.path.join(checkout_root, 'mach')
         if not os.path.exists(mach_binary):
             raise ValueError("mach not found at %s" % mach_binary)
 
         # If Python can't figure out what its own executable is, there's little
         # chance we're going to be able to execute mach on its own, particularly
         # on Windows.
         if not sys.executable:
             raise ValueError("cannot determine path to Python executable")
 
         cmd = [sys.executable, mach_binary, 'artifact', 'toolchain',
-               '--tooltool-manifest', abs_manifest_file,
-               'clang']
+               '--from-build', toolchain_job]
 
         subprocess.check_call(cmd, cwd=state_dir)
 
     def which(self, name):
         """Python implementation of which.
 
         It returns the path of an executable or None if it couldn't be found.
         """

--- a/python/mozboot/mozboot/stylo.py
+++ b/python/mozboot/mozboot/stylo.py
@@ -1,8 +1,8 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from __future__ import print_function, unicode_literals
 
-WINDOWS = 'browser/config/tooltool-manifests/win64/clang.manifest'
-LINUX = 'browser/config/tooltool-manifests/linux64/clang.manifest'
+WINDOWS = 'win64-clang-cl'
+LINUX = 'linux64-clang'