diff --git a/testing/marionette/driver.js b/testing/marionette/driver.js
index fbad2dd05764..f754f266ec0d 100644
--- a/testing/marionette/driver.js
+++ b/testing/marionette/driver.js
@@ -156,7 +156,6 @@ this.GeckoDriver = function (appName, server) {
     "acceptInsecureCerts": !this.secureTLS,
 
     // supported features
-    "raisesAccessibilityExceptions": false,
     "rotatable": this.appName == "B2G",
     "proxy": {},
 
@@ -164,6 +163,7 @@ this.GeckoDriver = function (appName, server) {
     "specificationLevel": 0,
     "moz:processID": Services.appinfo.processID,
     "moz:profile": Services.dirsvc.get("ProfD", Ci.nsIFile).path,
+    "moz:accessibilityChecks": false,
   };
 
   this.mm = globalMessageManager;
@@ -183,6 +183,10 @@ this.GeckoDriver = function (appName, server) {
   this.actions = new action.Chain();
 };
 
+Object.defineProperty(GeckoDriver.prototype, "a11yChecks", {
+  get: function () { return this.sessionCapabilities["moz:accessibilityChecks"]; }
+});
+
 GeckoDriver.prototype.QueryInterface = XPCOMUtils.generateQI([
   Ci.nsIMessageListener,
   Ci.nsIObserver,
@@ -532,8 +536,7 @@ GeckoDriver.prototype.newSession = function*(cmd, resp) {
   // If we are testing accessibility with marionette, start a11y service in
   // chrome first. This will ensure that we do not have any content-only
   // services hanging around.
-  if (this.sessionCapabilities.raisesAccessibilityExceptions &&
-      accessibility.service) {
+  if (this.a11yChecks && accessibility.service) {
     logger.info("Preemptively starting accessibility service in Chrome");
   }
 
@@ -1784,8 +1787,7 @@ GeckoDriver.prototype.clickElement = function*(cmd, resp) {
     case Context.CHROME:
       let win = this.getCurrentWindow();
       let el = this.curBrowser.seenEls.get(id, {frame: win});
-      yield interaction.clickElement(
-          el, this.sessionCapabilities.raisesAccessibilityExceptions);
+      yield interaction.clickElement(el, this.a11yChecks);
       break;
 
     case Context.CONTENT:
@@ -1915,7 +1917,7 @@ GeckoDriver.prototype.isElementDisplayed = function*(cmd, resp) {
       let win = this.getCurrentWindow();
       let el = this.curBrowser.seenEls.get(id, {frame: win});
       resp.body.value = yield interaction.isElementDisplayed(
-          el, this.sessionCapabilities.raisesAccessibilityExceptions);
+          el, this.a11yChecks);
       break;
 
     case Context.CONTENT:
@@ -1964,7 +1966,7 @@ GeckoDriver.prototype.isElementEnabled = function*(cmd, resp) {
       let win = this.getCurrentWindow();
       let el = this.curBrowser.seenEls.get(id, {frame: win});
       resp.body.value = yield interaction.isElementEnabled(
-          el, this.sessionCapabilities.raisesAccessibilityExceptions);
+          el, this.a11yChecks);
       break;
 
     case Context.CONTENT:
@@ -1988,7 +1990,7 @@ GeckoDriver.prototype.isElementSelected = function*(cmd, resp) {
       let win = this.getCurrentWindow();
       let el = this.curBrowser.seenEls.get(id, {frame: win});
       resp.body.value = yield interaction.isElementSelected(
-          el, this.sessionCapabilities.raisesAccessibilityExceptions);
+          el, this.a11yChecks);
       break;
 
     case Context.CONTENT:
@@ -2036,7 +2038,7 @@ GeckoDriver.prototype.sendKeysToElement = function*(cmd, resp) {
       let win = this.getCurrentWindow();
       let el = this.curBrowser.seenEls.get(id, {frame: win});
       yield interaction.sendKeysToElement(
-          el, value, true, this.sessionCapabilities.raisesAccessibilityExceptions);
+          el, value, true, this.a11yChecks);
       break;
 
     case Context.CONTENT:
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_accessibility.py b/testing/marionette/harness/marionette_harness/tests/unit/test_accessibility.py
index 22fd51ddaaed..03edb32486ce 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_accessibility.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_accessibility.py
@@ -90,10 +90,9 @@ class TestAccessibility(MarionetteTestCase):
             element = self.marionette.find_element(By.ID, id)
             testFn(element)
 
-    def setup_accessibility(self, raisesAccessibilityExceptions=True, navigate=True):
+    def setup_accessibility(self, enable_a11y_checks=True, navigate=True):
         self.marionette.delete_session()
-        self.marionette.start_session(
-            {"raisesAccessibilityExceptions": raisesAccessibilityExceptions})
+        self.marionette.start_session({"moz:accessibilityChecks": enable_a11y_checks})
         # Navigate to test_accessibility.html
         if navigate:
             test_accessibility = self.marionette.absolute_url("test_accessibility.html")
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py b/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py
index a7d0e3951d2d..8cbc0e319ecf 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py
@@ -48,6 +48,9 @@ class TestCapabilities(MarionetteTestCase):
         self.assertEqual(self.caps["moz:profile"], current_profile)
         self.assertEqual(self.marionette.profile, current_profile)
 
+        self.assertIn("moz:accessibilityChecks", self.caps)
+        self.assertFalse(self.caps["moz:accessibilityChecks"])
+
     def test_we_can_pass_in_capabilities_on_session_start(self):
         self.marionette.delete_session()
         capabilities = {"desiredCapabilities": {"somethingAwesome": "cake"}}
diff --git a/testing/marionette/listener.js b/testing/marionette/listener.js
index 4cf2b629f5b7..df0f13961939 100644
--- a/testing/marionette/listener.js
+++ b/testing/marionette/listener.js
@@ -634,7 +634,7 @@ function singleTap(id, corx, cory) {
     throw new ElementNotVisibleError("Element is not currently visible and may not be manipulated");
   }
 
-  let a11y = accessibility.get(capabilities.raisesAccessibilityExceptions);
+  let a11y = accessibility.get(capabilities["moz:accessibilityChecks"]);
   return a11y.getAccessible(el, true).then(acc => {
     a11y.assertVisible(acc, el, visible);
     a11y.assertActionable(acc, el);
@@ -1157,7 +1157,7 @@ function clickElement(id) {
   let el = seenEls.get(id, curContainer);
   return interaction.clickElement(
       el,
-      !!capabilities.raisesAccessibilityExceptions,
+      !!capabilities["moz:accessibilityChecks"],
       capabilities.specificationLevel >= 1);
 }
 
@@ -1216,7 +1216,7 @@ function getElementTagName(id) {
 function isElementDisplayed(id) {
   let el = seenEls.get(id, curContainer);
   return interaction.isElementDisplayed(
-      el, capabilities.raisesAccessibilityExceptions);
+      el, capabilities["moz:accessibilityChecks"]);
 }
 
 /**
@@ -1269,7 +1269,7 @@ function getElementRect(id) {
 function isElementEnabled(id) {
   let el = seenEls.get(id, curContainer);
   return interaction.isElementEnabled(
-      el, capabilities.raisesAccessibilityExceptions);
+      el, capabilities["moz:accessibilityChecks"]);
 }
 
 /**
@@ -1281,7 +1281,7 @@ function isElementEnabled(id) {
 function isElementSelected(id) {
   let el = seenEls.get(id, curContainer);
   return interaction.isElementSelected(
-      el, capabilities.raisesAccessibilityExceptions);
+      el, capabilities["moz:accessibilityChecks"]);
 }
 
 function* sendKeysToElement(id, val) {
@@ -1291,7 +1291,7 @@ function* sendKeysToElement(id, val) {
     yield interaction.uploadFile(el, path);
   } else {
     yield interaction.sendKeysToElement(
-        el, val, false, capabilities.raisesAccessibilityExceptions);
+        el, val, false, capabilities["moz:accessibilityChecks"]);
   }
 }