--- a/taskcluster/ci/build/windows.yml
+++ b/taskcluster/ci/build/windows.yml
@@ -523,17 +523,17 @@ win64-devedition-nightly/opt:
 win32-mingw32/debug:
     description: "Win32 MinGW Debug"
     index:
         product: firefox
         job-name: win32-mingw32-debug
     treeherder:
         platform: windows-mingw32-32/debug
         symbol: tc(B)
-        tier: 2
+        tier: 3
     worker-type: aws-provisioner-v1/gecko-{level}-b-linux
     worker:
         max-run-time: 7200
     run:
         using: mozharness
         script: mozharness/scripts/fx_desktop_build.py
         config:
             - builds/releng_base_windows_32_mingw_builds.py