--- a/accessible/tests/mochitest/hittest/a11y.ini
+++ b/accessible/tests/mochitest/hittest/a11y.ini
@@ -4,11 +4,12 @@ support-files = zoom_tree.xul
   !/accessible/tests/mochitest/letters.gif
 
 [test_browser.html]
 [test_canvas_hitregion.html]
 skip-if = (os == "android" || appname == "b2g")
 [test_general.html]
 [test_menu.xul]
 [test_shadowroot.html]
+skip-if = stylo # Stylo doesn't support shadow DOM yet, bug 1293844
 [test_zoom.html]
 [test_zoom_text.html]
 [test_zoom_tree.xul]

--- a/accessible/tests/mochitest/treeupdate/a11y.ini
+++ b/accessible/tests/mochitest/treeupdate/a11y.ini
@@ -10,16 +10,17 @@ support-files =
 [test_bug883708.xhtml]
 [test_bug884251.xhtml]
 [test_bug895082.html]
 [test_bug1040735.html]
 [test_bug1100602.html]
 [test_bug1175913.html]
 [test_bug1189277.html]
 [test_bug1276857.html]
+skip-if = stylo # Stylo doesn't support shadow DOM yet, bug 1293844
 [test_canvas.html]
 [test_colorpicker.xul]
 [test_contextmenu.xul]
 [test_cssoverflow.html]
 [test_deck.xul]
 [test_doc.html]
 [test_gencontent.html]
 [test_general.html]

--- a/testing/marionette/harness/marionette_harness/tests/unit/unit-tests.ini
+++ b/testing/marionette/harness/marionette_harness/tests/unit/unit-tests.ini
@@ -106,16 +106,17 @@ skip-if = appname == 'fennec'
 [test_teardown_context_preserved.py]
 [test_file_upload.py]
 skip-if = appname == 'fennec' || os == "win" # http://bugs.python.org/issue14574
 
 [test_execute_sandboxes.py]
 [test_prefs.py]
 
 [test_shadow_dom.py]
+skip-if = stylo # Stylo doesn't support shadow DOM yet, bug 1293844
 
 [test_chrome.py]
 skip-if = appname == 'fennec'
 
 [test_addons.py]
 skip-if = appname == 'fennec' # Bug 1330598
 
 [test_select.py]