--- a/taskcluster/ci/toolchain/windows.yml
+++ b/taskcluster/ci/toolchain/windows.yml
@@ -3,17 +3,17 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 win32-clang-cl:
     description: "Clang-cl toolchain build"
     treeherder:
         kind: build
         platform: toolchains/opt
         symbol: TW32(clang-cl)
-        tier: 2
+        tier: 1
     worker-type: aws-provisioner-v1/gecko-{level}-b-win2012
     worker:
         max-run-time: 36000
         env:
             TOOLTOOL_MANIFEST: "browser/config/tooltool-manifests/win32/build-clang-cl.manifest"
     run:
         using: toolchain-script
         script: build-clang32-windows.sh
@@ -24,17 +24,17 @@ win32-clang-cl:
         toolchain-artifact: public/build/clang.tar.bz2
 
 win64-clang-cl:
     description: "Clang-cl toolchain build"
     treeherder:
         kind: build
         platform: toolchains/opt
         symbol: TW64(clang-cl)
-        tier: 2
+        tier: 1
     worker-type: aws-provisioner-v1/gecko-{level}-b-win2012
     worker:
         max-run-time: 36000
         env:
             TOOLTOOL_MANIFEST: "browser/config/tooltool-manifests/win32/build-clang-cl.manifest"
     run:
         using: toolchain-script
         script: build-clang64-windows.sh