--- a/taskcluster/actions/test-retrigger-action.py
+++ b/taskcluster/actions/test-retrigger-action.py
@@ -17,17 +17,18 @@ TASKCLUSTER_QUEUE_URL = "https://queue.t
 logger = logging.getLogger(__name__)
 
 
 @register_callback_action(
     title='Schedule test retrigger',
     symbol='tr',
     description="Retriggers the specified test job with additional options",
     context=[{'test-type': 'mochitest'},
-             {'test-type': 'reftest'}],
+             {'test-type': 'reftest'},
+             {'test-type': 'web-platform-tests'}],
     order=0,
     schema={
         'type': 'object',
         'properties': {
             'path': {
                 'type': 'string',
                 'maxLength': 255,
                 'default': '',
@@ -101,17 +102,20 @@ def test_retrigger_action(parameters, in
     enable_e10s = json.loads(new_task_definition['payload']['env'].get(
         'ENABLE_E10S', 'true'))
     if not enable_e10s:
         custom_mach_command += ['--disable-e10s']
 
     custom_mach_command += ['--log-tbpl=-',
                             '--log-tbpl-level={}'.format(input['logLevel'])]
     if input.get('runUntilFail'):
-        custom_mach_command += ['--run-until-failure']
+        if task['tags']['test-type'] == 'web-platform-tests':
+            custom_mach_command += ['--repeat-until-unexpected']
+        else:
+            custom_mach_command += ['--run-until-failure']
     if input.get('repeat'):
         custom_mach_command += ['--repeat', str(input['repeat'])]
 
     # add any custom gecko preferences
     for (key, val) in input.get('preferences', {}).iteritems():
         custom_mach_command += ['--setpref', '{}={}'.format(key, val)]
 
     custom_mach_command += [input['path']]