--- a/taskcluster/ci/legacy/tasks/builds/mulet_linux.yml
+++ b/taskcluster/ci/legacy/tasks/builds/mulet_linux.yml
@@ -43,16 +43,17 @@ task:
 
   extra:
     treeherderEnv:
       - production
       - staging
     treeherder:
       # Disable "TC" prefix...
       groupSymbol: "?"
+      tier: 3
       machine:
         platform: mulet-linux64
     # 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: 'public/build/target.tar.bz2'
       test_packages: 'public/build/target.test_packages.json'

--- a/taskcluster/ci/legacy/tasks/builds/mulet_linux_dbg.yml
+++ b/taskcluster/ci/legacy/tasks/builds/mulet_linux_dbg.yml
@@ -43,16 +43,17 @@ task:
 
   extra:
     treeherderEnv:
       - production
       - staging
     treeherder:
       # Disable "TC" prefix...
       groupSymbol: "?"
+      tier: 3
       machine:
         platform: mulet-linux64
       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: