diff --git a/Libraries/LibWeb/HTML/MessageEvent.idl b/Libraries/LibWeb/HTML/MessageEvent.idl
index a85cb1e3eb1..24b3201258b 100644
--- a/Libraries/LibWeb/HTML/MessageEvent.idl
+++ b/Libraries/LibWeb/HTML/MessageEvent.idl
@@ -13,7 +13,7 @@ interface MessageEvent : Event {
     readonly attribute USVString origin;
     readonly attribute DOMString lastEventId;
     readonly attribute MessageEventSource? source;
-    // FIXME: readonly attribute FrozenArray<MessagePort> ports;
+    // FIXME: This should be FrozenArray<MessagePort>, but must also always return the same object.
     readonly attribute any ports;
 
     undefined initMessageEvent(DOMString type, optional boolean bubbles = false, optional boolean cancelable = false, optional any data = null, optional USVString origin = "", optional DOMString lastEventId = "", optional MessageEventSource? source = null, optional sequence<MessagePort> ports = []);
diff --git a/Libraries/LibWeb/PerformanceTimeline/PerformanceObserver.idl b/Libraries/LibWeb/PerformanceTimeline/PerformanceObserver.idl
index d8818b111c6..c11d8411ff3 100644
--- a/Libraries/LibWeb/PerformanceTimeline/PerformanceObserver.idl
+++ b/Libraries/LibWeb/PerformanceTimeline/PerformanceObserver.idl
@@ -21,6 +21,6 @@ interface PerformanceObserver {
     undefined observe(optional PerformanceObserverInit options = {});
     undefined disconnect();
     PerformanceEntryList takeRecords();
-    // FIXME: [SameObject] static readonly attribute FrozenArray<DOMString> supportedEntryTypes;
+    // FIXME: This should be FrozenArray<DOMString>, but must also always return the same object.
     [SameObject] static readonly attribute any supportedEntryTypes;
 };