diff --git a/Userland/Libraries/LibWeb/HTML/Timer.cpp b/Userland/Libraries/LibWeb/HTML/Timer.cpp
index 1ea86148f6..b2e75fbdbc 100644
--- a/Userland/Libraries/LibWeb/HTML/Timer.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Timer.cpp
@@ -10,24 +10,29 @@
 
 namespace Web::HTML {
 
-NonnullRefPtr<Timer> Timer::create(Window& window, i32 milliseconds, Function<void()> callback, i32 id)
+JS::NonnullGCPtr<Timer> Timer::create(Window& window, i32 milliseconds, Function<void()> callback, i32 id)
 {
-    return adopt_ref(*new Timer(window, milliseconds, move(callback), id));
+    return *window.heap().allocate_without_realm<Timer>(window, milliseconds, move(callback), id);
 }
 
 Timer::Timer(Window& window, i32 milliseconds, Function<void()> callback, i32 id)
     : m_window(window)
+    , m_callback(move(callback))
     , m_id(id)
 {
-    m_timer = Core::Timer::create_single_shot(milliseconds, [this, callback = move(callback)] {
-        NonnullRefPtr strong_timer { *this };
-        callback();
+    m_timer = Core::Timer::create_single_shot(milliseconds, [this] {
+        m_callback();
     });
 }
 
+void Timer::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_window.ptr());
+}
+
 Timer::~Timer()
 {
-    m_window.deallocate_timer_id({}, m_id);
 }
 
 void Timer::start()
diff --git a/Userland/Libraries/LibWeb/HTML/Timer.h b/Userland/Libraries/LibWeb/HTML/Timer.h
index 66553028a8..aa2edfb3f5 100644
--- a/Userland/Libraries/LibWeb/HTML/Timer.h
+++ b/Userland/Libraries/LibWeb/HTML/Timer.h
@@ -8,23 +8,31 @@
 
 #include <AK/Forward.h>
 #include <AK/Function.h>
+#include <AK/WeakPtr.h>
 #include <LibCore/Forward.h>
+#include <LibJS/Heap/Cell.h>
+#include <LibJS/Heap/GCPtr.h>
 #include <LibWeb/Forward.h>
 
 namespace Web::HTML {
 
-class Timer final : public RefCounted<Timer> {
+class Timer final : public JS::Cell {
+    JS_CELL(Timer, JS::Cell);
+
 public:
-    static NonnullRefPtr<Timer> create(Window& window, i32 milliseconds, Function<void()> callback, i32 id);
-    ~Timer();
+    static JS::NonnullGCPtr<Timer> create(Window&, i32 milliseconds, Function<void()> callback, i32 id);
+    virtual ~Timer() override;
 
     void start();
 
 private:
     Timer(Window& window, i32 milliseconds, Function<void()> callback, i32 id);
 
+    virtual void visit_edges(Cell::Visitor&) override;
+
     RefPtr<Core::Timer> m_timer;
-    Window& m_window;
+    JS::NonnullGCPtr<Window> m_window;
+    Function<void()> m_callback;
     i32 m_id { 0 };
 };
 
diff --git a/Userland/Libraries/LibWeb/HTML/Window.cpp b/Userland/Libraries/LibWeb/HTML/Window.cpp
index 942ac9be98..b03ae4d6a1 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Window.cpp
@@ -118,6 +118,8 @@ void Window::visit_edges(JS::Cell::Visitor& visitor)
         visitor.visit(it.value);
     for (auto& it : m_constructors)
         visitor.visit(it.value);
+    for (auto& it : m_timers)
+        visitor.visit(it.value.ptr());
 }
 
 Window::~Window() = default;
diff --git a/Userland/Libraries/LibWeb/HTML/Window.h b/Userland/Libraries/LibWeb/HTML/Window.h
index 463eb28e51..32b9899f79 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.h
+++ b/Userland/Libraries/LibWeb/HTML/Window.h
@@ -144,7 +144,7 @@ private:
     JS::GCPtr<DOM::Event> m_current_event;
 
     IDAllocator m_timer_id_allocator;
-    HashMap<int, NonnullRefPtr<Timer>> m_timers;
+    HashMap<int, JS::NonnullGCPtr<Timer>> m_timers;
 
     JS::GCPtr<HighResolutionTime::Performance> m_performance;
     NonnullRefPtr<Crypto::Crypto> m_crypto;