diff --git a/explainer.md b/explainer.md
index d0bf1456..80999ec0 100644
--- a/explainer.md
+++ b/explainer.md
@@ -796,6 +796,6 @@ partial dictionary WebGLContextAttributes {
 };
 
 partial interface WebGLRenderingContextBase {
-    Promise<void> makeXRCompatible();
+    [NewObject] Promise<void> makeXRCompatible();
 };
 ```
diff --git a/index.bs b/index.bs
index f6bdd8fd..c7136ec4 100644
--- a/index.bs
+++ b/index.bs
@@ -1856,7 +1856,7 @@ partial dictionary WebGLContextAttributes {
 };
 
 partial interface mixin WebGLRenderingContextBase {
-    Promise&lt;void&gt; makeXRCompatible();
+    [NewObject] Promise&lt;void&gt; makeXRCompatible();
 };
 </pre>