diff --git a/moli-renderer-v8/src/context_bootstrap/window_accessors.rs b/moli-renderer-v8/src/context_bootstrap/window_accessors.rs
index 593f391b67..2c72182646 100644
--- a/moli-renderer-v8/src/context_bootstrap/window_accessors.rs
+++ b/moli-renderer-v8/src/context_bootstrap/window_accessors.rs
@@ -29,9 +29,9 @@ pub(crate) use document::{
 pub(crate) use helpers::{current_window_style_viewport, window_host_ptr};
 pub(super) use helpers::{window_child_context_handle, window_current_dispatch_scope, window_has_discarded_child_browsing_context};
 pub(super) use interceptors::{
-    window_indexed_property_descriptor, window_indexed_property_enumerator,
-    window_indexed_property_getter, window_indexed_property_query,
-    window_named_properties_indexed_property_getter,
+    window_indexed_property_deleter, window_indexed_property_descriptor,
+    window_indexed_property_enumerator, window_indexed_property_getter,
+    window_indexed_property_query, window_named_properties_indexed_property_getter,
     window_named_properties_indexed_property_query, window_named_property_getter,
     window_named_property_query,
 };
diff --git a/moli-renderer-v8/src/context_bootstrap/window_accessors/interceptors.rs b/moli-renderer-v8/src/context_bootstrap/window_accessors/interceptors.rs
index 131310c74c..c844962fdf 100644
--- a/moli-renderer-v8/src/context_bootstrap/window_accessors/interceptors.rs
+++ b/moli-renderer-v8/src/context_bootstrap/window_accessors/interceptors.rs
@@ -78,6 +78,19 @@ pub(in crate::context_bootstrap) fn window_indexed_property_query<'s>(
     v8::Intercepted::kYes
 }
 
+pub(in crate::context_bootstrap) fn window_indexed_property_deleter<'s>(
+    scope: &mut v8::PinScope<'s, '_>,
+    index: u32,
+    args: v8::PropertyCallbackArguments<'s>,
+    mut rv: v8::ReturnValue<'_, v8::Boolean>,
+) -> v8::Intercepted {
+    if window_indexed_child_handle(scope, args.holder(), index).is_none() {
+        return v8::Intercepted::kNo;
+    }
+    rv.set_bool(false);
+    v8::Intercepted::kYes
+}
+
 pub(in crate::context_bootstrap) fn window_indexed_property_enumerator<'s>(
     scope: &mut v8::PinScope<'s, '_>,
     args: v8::PropertyCallbackArguments<'s>,
diff --git a/moli-renderer-v8/src/context_bootstrap/window_template.rs b/moli-renderer-v8/src/context_bootstrap/window_template.rs
index 41adc6e5bb..91cd5003b3 100644
--- a/moli-renderer-v8/src/context_bootstrap/window_template.rs
+++ b/moli-renderer-v8/src/context_bootstrap/window_template.rs
@@ -363,6 +363,7 @@ pub(crate) fn install_window_own_template_bindings<'s>(
         v8::IndexedPropertyHandlerConfiguration::new()
             .getter(window_indexed_property_getter)
             .query(window_indexed_property_query)
+            .deleter(window_indexed_property_deleter)
             .enumerator(window_indexed_property_enumerator)
             .descriptor(window_indexed_property_descriptor),
     );
diff --git a/moli-renderer-v8/src/script_vm/tests/dom_elements/dom_surface/extracted/frame_navigation_and_history.rs b/moli-renderer-v8/src/script_vm/tests/dom_elements/dom_surface/extracted/frame_navigation_and_history.rs
index 5784575d80..a7ffb8bec5 100644
--- a/moli-renderer-v8/src/script_vm/tests/dom_elements/dom_surface/extracted/frame_navigation_and_history.rs
+++ b/moli-renderer-v8/src/script_vm/tests/dom_elements/dom_surface/extracted/frame_navigation_and_history.rs
@@ -4543,3 +4543,41 @@ async fn child_meta_refresh_after_same_document_navigation_uses_child_referrer()
         Some(child_url.as_str())
     );
 }
+
+#[test]
+fn main_window_indexed_child_deletion_is_live_and_not_cached() {
+    let mut vm = new_storage_test_vm("https://window-indexed-delete.test/");
+
+    let result = vm
+        .eval(
+            r#"
+(() => {
+  const frame = document.createElement('iframe');
+  frame.srcdoc = '';
+  let absentDeletesSucceeded = true;
+  for (let i = 0; i < 1e5; i++) {
+    absentDeletesSucceeded &&= delete window[0];
+  }
+  (document.body || document.documentElement || document).appendChild(frame);
+  const presentAfterAbsent = delete window[0];
+  let presentDeletesFailed = true;
+  for (let i = 0; i < 1e5; i++) {
+    presentDeletesFailed &&= !delete window[0];
+  }
+  frame.remove();
+  return JSON.stringify({
+    absentDeletesSucceeded,
+    presentAfterAbsent,
+    presentDeletesFailed,
+    absentAfterPresent: delete window[0]
+  });
+})()
+"#,
+        )
+        .expect("live Window indexed deletion probe should evaluate");
+
+    assert_eq!(
+        result,
+        r#"{"absentDeletesSucceeded":true,"presentAfterAbsent":false,"presentDeletesFailed":true,"absentAfterPresent":true}"#
+    );
+}