diff --git a/components/script/dom/webidls/XR.webidl b/components/script/dom/webidls/XR.webidl
index 4a6bca26a69..58732edd42b 100644
--- a/components/script/dom/webidls/XR.webidl
+++ b/components/script/dom/webidls/XR.webidl
@@ -28,3 +28,8 @@ dictionary XRSessionCreationOptions {
   XRSessionMode mode = "inline";
   // XRPresentationContext outputContext;
 };
+
+partial interface XR {
+  // https://github.com/immersive-web/webxr-test-api/
+  [SameObject, Pref="dom.webxr.test"] readonly attribute XRTest test;
+};
diff --git a/components/script/dom/xr.rs b/components/script/dom/xr.rs
index 3ff67b0042c..1626ad4e00e 100644
--- a/components/script/dom/xr.rs
+++ b/components/script/dom/xr.rs
@@ -21,6 +21,7 @@ use crate::dom::promise::Promise;
 use crate::dom::vrdisplay::VRDisplay;
 use crate::dom::vrdisplayevent::VRDisplayEvent;
 use crate::dom::xrsession::XRSession;
+use crate::dom::xrtest::XRTest;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
 use profile_traits::ipc;
@@ -36,6 +37,7 @@ pub struct XR {
     gamepads: DomRefCell<Vec<Dom<Gamepad>>>,
     pending_immersive_session: Cell<bool>,
     active_immersive_session: MutNullableDom<VRDisplay>,
+    test: MutNullableDom<XRTest>,
 }
 
 impl XR {
@@ -46,6 +48,7 @@ impl XR {
             gamepads: DomRefCell::new(Vec::new()),
             pending_immersive_session: Cell::new(false),
             active_immersive_session: Default::default(),
+            test: Default::default(),
         }
     }
 
@@ -141,6 +144,11 @@ impl XRMethods for XR {
         session.xr_present(promise.clone());
         promise
     }
+
+    // https://github.com/immersive-web/webxr-test-api/blob/master/explainer.md
+    fn Test(&self) -> DomRoot<XRTest> {
+        self.test.or_init(|| XRTest::new(&self.global()))
+    }
 }
 
 impl XR {
diff --git a/python/tidy/servo_tidy/tidy.py b/python/tidy/servo_tidy/tidy.py
index 35ebcb656db..0fdda070899 100644
--- a/python/tidy/servo_tidy/tidy.py
+++ b/python/tidy/servo_tidy/tidy.py
@@ -98,6 +98,7 @@ WEBIDL_STANDARDS = [
     "//wicg.github.io",
     "//webaudio.github.io",
     "//immersive-web.github.io/",
+    "//github.com/immersive-web/webxr-test-api/",
     # Not a URL
     "// This interface is entirely internal to Servo, and should not be" +
     " accessible to\n// web pages."