diff --git a/components/script/dom/webidls/XRFrame.webidl b/components/script/dom/webidls/XRFrame.webidl
index 24f714fcb76..4a8159177d8 100644
--- a/components/script/dom/webidls/XRFrame.webidl
+++ b/components/script/dom/webidls/XRFrame.webidl
@@ -8,6 +8,6 @@
 interface XRFrame {
   readonly attribute XRSession session;
 
-  XRViewerPose? getViewerPose(XRReferenceSpace referenceSpace);
+  [Throws] XRViewerPose? getViewerPose(XRReferenceSpace referenceSpace);
   // XRInputPose? getInputPose(XRInputSource inputSource, optional XRReferenceSpace referenceSpace);
 };
diff --git a/components/script/dom/xrframe.rs b/components/script/dom/xrframe.rs
index c9bb240a3bf..a3a8c201255 100644
--- a/components/script/dom/xrframe.rs
+++ b/components/script/dom/xrframe.rs
@@ -4,6 +4,8 @@
 
 use crate::dom::bindings::codegen::Bindings::XRFrameBinding;
 use crate::dom::bindings::codegen::Bindings::XRFrameBinding::XRFrameMethods;
+use crate::dom::bindings::error::Error;
+use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::globalscope::GlobalScope;
@@ -50,13 +52,19 @@ impl XRFrameMethods for XRFrame {
     }
 
     /// https://immersive-web.github.io/webxr/#dom-xrframe-getviewerpose
-    fn GetViewerPose(&self, reference: &XRReferenceSpace) -> Option<DomRoot<XRViewerPose>> {
+    fn GetViewerPose(
+        &self,
+        reference: &XRReferenceSpace,
+    ) -> Result<Option<DomRoot<XRViewerPose>>, Error> {
+        if self.session != reference.upcast::<XRSpace>().session() {
+            return Err(Error::InvalidState);
+        }
         let pose = reference.get_viewer_pose(&self.data);
-        Some(XRViewerPose::new(
+        Ok(Some(XRViewerPose::new(
             &self.global(),
             &self.session,
             pose,
             &self.data,
-        ))
+        )))
     }
 }
diff --git a/components/script/dom/xrspace.rs b/components/script/dom/xrspace.rs
index d9b5a1fc983..d9bbad8cd86 100644
--- a/components/script/dom/xrspace.rs
+++ b/components/script/dom/xrspace.rs
@@ -44,7 +44,6 @@ impl XRSpace {
     /// The reference origin used is common between all
     /// get_pose calls for spaces from the same device, so this can be used to compare
     /// with other spaces
-    #[allow(unused)]
     pub fn get_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
         if let Some(reference) = self.downcast::<XRReferenceSpace>() {
             reference.get_pose(base_pose)
@@ -65,4 +64,8 @@ impl XRSpace {
         );
         RigidTransform3D::new(rotation, translation)
     }
+
+    pub fn session(&self) -> &XRSession {
+        &self.session
+    }
 }