--- a/taskcluster/ci/legacy/tasks/builds/haz_shell_linux.yml
+++ b/taskcluster/ci/legacy/tasks/builds/haz_shell_linux.yml
@@ -43,16 +43,17 @@ task:
       - staging
     treeherder:
       machine:
         # see https://github.com/mozilla/treeherder/blob/master/ui/js/values.js
         platform: linux64
       groupSymbol: SM-tc
       groupName: SpiderMonkey, submitted by taskcluster
       symbol: H
+      tier: 1
       collection:
         debug: true
     # Rather then enforcing particular conventions we require that all build
     # tasks provide the "build" extra field to specify where the build and tests
     # files are located.
     locations:
       build: null
       tests: null