diff --git a/components/script/dom/dedicatedworkerglobalscope.rs b/components/script/dom/dedicatedworkerglobalscope.rs
index b6f6914a50c..4f0bad72949 100644
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@@ -358,6 +358,7 @@ impl DedicatedWorkerGlobalScope {
         self.in_error_reporting_mode.set(true);
 
         // Steps 3-12.
+        // FIXME(#13195): muted errors.
         let event = ErrorEvent::new(GlobalRef::Worker(self.upcast()),
                                     atom!("error"),
                                     EventBubbles::DoesNotBubble,
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index e28b381a2fa..4954f7cccd0 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -1766,6 +1766,7 @@ impl Window {
         self.in_error_reporting_mode.set(true);
 
         // Steps 3-12.
+        // FIXME(#13195): muted errors.
         let event = ErrorEvent::new(GlobalRef::Window(self),
                                     atom!("error"),
                                     EventBubbles::DoesNotBubble,