diff --git a/Libraries/LibWeb/HTML/CloseWatcher.cpp b/Libraries/LibWeb/HTML/CloseWatcher.cpp
index f162b8be3eb..9e42ce5ea41 100644
--- a/Libraries/LibWeb/HTML/CloseWatcher.cpp
+++ b/Libraries/LibWeb/HTML/CloseWatcher.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2024, the Ladybird developers.
+ * Copyright (c) 2024, Felipe Muñoz Mazur <felipe.munoz.mazur@protonmail.com>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -57,9 +58,17 @@ WebIDL::ExceptionOr<GC::Ref<CloseWatcher>> CloseWatcher::construct_impl(JS::Real
     auto close_watcher = establish(window);
 
     // 3. If options["signal"] exists, then:
-    if (options.signal) {
-        // FIXME: 3.1 If options["signal"]'s aborted, then destroy closeWatcher.
-        // FIXME: 3.2 Add the following steps to options["signal"]:
+    if (auto signal = options.signal) {
+        // 3.1 If options["signal"]'s aborted, then destroy closeWatcher.
+        if (signal->aborted()) {
+            close_watcher->destroy();
+        }
+
+        // 3.2 Add the following steps to options["signal"]:
+        signal->add_abort_algorithm([close_watcher] {
+            // 3.2.1 Destroy closeWatcher.
+            close_watcher->destroy();
+        });
     }
 
     return close_watcher;
diff --git a/Tests/LibWeb/Text/expected/CloseWatcher-abort-requestClose.txt b/Tests/LibWeb/Text/expected/CloseWatcher-abort-requestClose.txt
new file mode 100644
index 00000000000..4b095fd0ff9
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/CloseWatcher-abort-requestClose.txt
@@ -0,0 +1,2 @@
+false
+false
diff --git a/Tests/LibWeb/Text/expected/CloseWatcher-already-aborted.txt b/Tests/LibWeb/Text/expected/CloseWatcher-already-aborted.txt
new file mode 100644
index 00000000000..4b095fd0ff9
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/CloseWatcher-already-aborted.txt
@@ -0,0 +1,2 @@
+false
+false
diff --git a/Tests/LibWeb/Text/expected/CloseWatcher-fire-once.txt b/Tests/LibWeb/Text/expected/CloseWatcher-fire-once.txt
new file mode 100644
index 00000000000..6ed281c757a
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/CloseWatcher-fire-once.txt
@@ -0,0 +1,2 @@
+1
+1
diff --git a/Tests/LibWeb/Text/input/CloseWatcher-abort-requestClose.html b/Tests/LibWeb/Text/input/CloseWatcher-abort-requestClose.html
new file mode 100644
index 00000000000..36bb3747e7a
--- /dev/null
+++ b/Tests/LibWeb/Text/input/CloseWatcher-abort-requestClose.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<script src="include.js"></script>
+<script>
+    test(() => {
+        let controller = new AbortController();
+        let watcher = new CloseWatcher({ signal: controller.signal });
+        let oncancel_called = false;
+        let onclose_called = false;
+        watcher.oncancel = () => oncancel_called = true;
+        watcher.onclose = () => onclose_called = true;
+
+        controller.abort();
+        watcher.requestClose();
+
+        println(oncancel_called);
+        println(onclose_called);
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/CloseWatcher-already-aborted.html b/Tests/LibWeb/Text/input/CloseWatcher-already-aborted.html
new file mode 100644
index 00000000000..722b3ed59cb
--- /dev/null
+++ b/Tests/LibWeb/Text/input/CloseWatcher-already-aborted.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<script src="include.js"></script>
+<script>
+    test(() => {
+        let watcher = new CloseWatcher({ signal: AbortSignal.abort() });
+        let oncancel_called = false;
+        let onclose_called = false;
+        watcher.oncancel = () => oncancel_called = true;
+        watcher.onclose = () => onclose_called = true;
+
+        watcher.requestClose();
+
+        println(oncancel_called);
+        println(onclose_called);
+    });
+
+</script>
diff --git a/Tests/LibWeb/Text/input/CloseWatcher-fire-once.html b/Tests/LibWeb/Text/input/CloseWatcher-fire-once.html
new file mode 100644
index 00000000000..a2f08d41c4e
--- /dev/null
+++ b/Tests/LibWeb/Text/input/CloseWatcher-fire-once.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<script src="include.js"></script>
+<script>
+    test(() => {
+        let controller = new AbortController();
+        let watcher = new CloseWatcher({ signal: controller.signal });
+        let oncancel_call_count_ = 0;
+        let onclose_call_count_ = 0;
+        watcher.oncancel = () => oncancel_call_count_++;
+        watcher.onclose = () => onclose_call_count_++;
+
+        watcher.requestClose();
+        controller.abort();
+
+        println(oncancel_call_count_);
+        println(onclose_call_count_);
+    })
+</script>
