diff --git a/etc/taskcluster/macos/config/roster b/etc/taskcluster/macos/config/roster
index 4bc8e4f718f..0ac80407a76 100644
--- a/etc/taskcluster/macos/config/roster
+++ b/etc/taskcluster/macos/config/roster
@@ -8,3 +8,5 @@ mac4:
     host: servo-tc-mac4.servo.org
 mac5:
     host: servo-tc-mac5.servo.org
+mac6:
+    host: servo-tc-mac6.servo.org