--- a/taskcluster/taskgraph/transforms/tests/android_test.py
+++ b/taskcluster/taskgraph/transforms/tests/android_test.py
@@ -21,16 +21,28 @@ def set_defaults(config, tests):
         # all Android test tasks download internal objects from tooltool
         test['mozharness']['tooltool-downloads'] = True
         test['mozharness']['build-artifact-name'] = 'public/build/target.apk'
         test['mozharness']['actions'] = ['get-secrets']
         yield test
 
 
 @transforms.add
+def set_tier(config, tests):
+    for test in tests:
+        if 'tier' not in test:
+            # Bug 1282850: android debug is tier 1, but opt is tier 2
+            if test['test-platform'] == 'android-4.3-arm7-api-15/debug':
+                test['tier'] = 1
+            else:
+                test['tier'] = 2
+        yield test
+
+
+@transforms.add
 def set_treeherder_machine_platform(config, tests):
     """Set the appropriate task.extra.treeherder.machine.platform"""
     # The build names for these build platforms have partially evolved over the
     # years..  This is temporary until we can clean up the handling of
     # platforms
     translation = {
         'android-api-15/debug': 'android-4-3-armv7-api15/debug',
         'android-api-15/opt': 'android-4-3-armv7-api15/opt',