diff --git a/Userland/Libraries/LibWeb/Bindings/Replaceable.h b/Userland/Libraries/LibWeb/Bindings/Replaceable.h
new file mode 100644
index 0000000000..6617922fe9
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Bindings/Replaceable.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#define REPLACEABLE_PROPERTY_SETTER(ObjectType, property)                                                                                 \
+    auto this_value = vm.this_value(global_object);                                                                                       \
+    if (!this_value.is_object() || !is<ObjectType>(this_value.as_object())) {                                                             \
+        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, #ObjectType);                                  \
+        return {};                                                                                                                        \
+    }                                                                                                                                     \
+    this_value.as_object().internal_define_own_property(#property, JS::PropertyDescriptor { .value = vm.argument(0), .writable = true }); \
+    return JS::js_undefined();