diff --git a/dom/telephony/test/marionette/manifest.ini b/dom/telephony/test/marionette/manifest.ini
index c8bd4186f3b..451697305ff 100644
--- a/dom/telephony/test/marionette/manifest.ini
+++ b/dom/telephony/test/marionette/manifest.ini
@@ -35,6 +35,7 @@ disabled = Bug 806138
 [test_swap_held_and_active.js]
 [test_incoming_onstatechange.js]
 [test_outgoing_onstatechange.js]
+disabled = Bug 821966
 [test_redundant_operations.js]
 disabled = Bug 821927
 [test_multiple_hold.js]