--- a/taskcluster/taskgraph/transforms/job/mozharness_test.py
+++ b/taskcluster/taskgraph/transforms/job/mozharness_test.py
@@ -308,16 +308,19 @@ def mozharness_test_on_generic_worker(co
             mh_command.append('--total-chunk={}'.format(test['chunks']))
             mh_command.append('--this-chunk={}'.format(test['this-chunk']))
         elif mozharness['chunking-args'] == 'test-suite-suffix':
             suffix = mozharness['chunk-suffix'].replace('<CHUNK>', str(test['this-chunk']))
             for i, c in enumerate(mh_command):
                 if isinstance(c, basestring) and c.startswith('--test-suite'):
                     mh_command[i] += suffix
 
+    if config.params['project'] == 'try':
+        env['TRY_COMMIT_MSG'] = config.params['message']
+
     worker['mounts'] = [{
         'directory': '.',
         'content': {
             'artifact': 'public/build/mozharness.zip',
             'task-id': {
                 'task-reference': '<build>'
             }
         },