--- a/taskcluster/ci/test/marionette.yml
+++ b/taskcluster/ci/test/marionette.yml
@@ -17,16 +17,20 @@ job-defaults:
                     - marionette/windows_taskcluster_config.py
                 default:
                     - marionette/prod_config.py
                     - remove_executables.py
 
 marionette:
     description: "Marionette unittest run"
     treeherder-symbol: Mn
+    run-on-projects:
+        by-test-platform:
+            android-em.*: ["trunk", "try"]
+            default: built-projects
     max-run-time:
         by-test-platform:
             android-em.*: 3600
             default: 5400
     instance-size:
         by-test-platform:
             android-em.*: xlarge
             default: default