diff --git a/src/master/wpt_run_step.py b/src/master/wpt_run_step.py
index 1911be19c..34026d852 100644
--- a/src/master/wpt_run_step.py
+++ b/src/master/wpt_run_step.py
@@ -91,7 +91,8 @@ def makeWptRunCommand(properties):
             # Chrome to call getUserMedia without failing out.
             command.extend([
                 '--binary-arg=--use-fake-ui-for-media-stream',
-                '--binary-arg=--use-fake-device-for-media-stream'
+                '--binary-arg=--use-fake-device-for-media-stream',
+                '--binary-arg=--enable-blink-features=MojoJS,MojoJSTest'
             ])
 
             if properties.getProperty('browser_channel') == 'experimental':