diff --git a/tests/wpt/mozilla/tests/webxr/obtain_frame.html b/tests/wpt/mozilla/tests/webxr/obtain_frame.html
index 902b0aecb44..dd491514f79 100644
--- a/tests/wpt/mozilla/tests/webxr/obtain_frame.html
+++ b/tests/wpt/mozilla/tests/webxr/obtain_frame.html
@@ -12,7 +12,7 @@
           let gl = canvas.getContext('webgl');
           promise_test(async function() {
             let mock = await navigator.xr.test.simulateDeviceConnection({supportsImmersive: true});
-            mock.setViewerOrigin({position: [0.5, 0, 0, 1], orientation: [0, 0, 0, 1] });
+            mock.setViewerOrigin({position: [0.5, 0.1, 0.1, 1], orientation: [1, 0, 0, 1] });
             mock.setViews(TEST_VIEWS);
             let session = await navigator.xr.requestSession({mode: "immersive-vr"});
             await session.updateRenderState({"baseLayer": new XRWebGLLayer(session, gl, {})});
@@ -28,18 +28,18 @@
               assert_matrix_approx_equals(view.projectionMatrix, VALID_PROJECTION_MATRIX, 0.001, "left projection matrix");
 
               if (view.eye == "left") {
-                assert_matrix_approx_equals(view.transform.matrix, [1,0,0,0, 0,1,0,0, 0,0,1,0, 0.4,0,0,1], 0.001, "left transform");
+                assert_matrix_approx_equals(view.transform.matrix, [1,0,0,0,0,0,1,0,0,-1,0,0,0.4,0.1,0.1,1], 0.001, "left transform");
                 let position = view.transform.position;
                 assert_approx_equals(position.x, 0.4, 0.001, "left x value");
-                assert_approx_equals(position.y, 0, 0.001, "left y value");
-                assert_approx_equals(position.z, 0, 0.001, "left z value");
+                assert_approx_equals(position.y, 0.1, 0.001, "left y value");
+                assert_approx_equals(position.z, 0.1, 0.001, "left z value");
                 assert_approx_equals(position.w, 1, 0.001, "left w value");
               } else if (view.eye == "right") {
-                assert_matrix_approx_equals(view.transform.matrix, [1,0,0,0, 0,1,0,0, 0,0,1,0, 0.6,0,0,1], 0.001, "right transform");
+                assert_matrix_approx_equals(view.transform.matrix, [1,0,0,0,0,0,1,0,0,-1,0,0,0.6,0.1,0.1,1], 0.001, "right transform");
                 let position = view.transform.position;
                 assert_approx_equals(position.x, 0.6, 0.001, "left x value");
-                assert_approx_equals(position.y, 0, 0.001, "left y value");
-                assert_approx_equals(position.z, 0, 0.001, "left z value");
+                assert_approx_equals(position.y, 0.1, 0.001, "left y value");
+                assert_approx_equals(position.z, 0.1, 0.001, "left z value");
                 assert_approx_equals(position.w, 1, 0.001, "left w value");
               } else {
                 throw "got unknown view";
diff --git a/tests/wpt/mozilla/tests/webxr/resources/webxr-util.js b/tests/wpt/mozilla/tests/webxr/resources/webxr-util.js
index 505173c8299..dc9ff1adc51 100644
--- a/tests/wpt/mozilla/tests/webxr/resources/webxr-util.js
+++ b/tests/wpt/mozilla/tests/webxr/resources/webxr-util.js
@@ -7,7 +7,7 @@ const RIGHT_OFFSET = {position: [0.1, 0, 0], orientation: [0,0,0,0]};
 let assert_matrix_approx_equals = function(m1, m2, epsilon, prefix = "") {
   assert_equals(m1.length, m2.length, prefix + "Matrix lengths should match");
   for(var i = 0; i < m1.length; ++i) {
-    assert_approx_equals(m1[i], m2[i], epsilon, m1 + prefix + "Component number " + i + " should match");
+    assert_approx_equals(m1[i], m2[i], epsilon, prefix + "Component number " + i + " should match");
   }
 }