diff --git a/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp b/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
index e631359ac1..b6a7e86383 100644
--- a/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
+++ b/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
@@ -769,7 +769,7 @@ Object* create_mapped_arguments_object(GlobalObject& global_object, FunctionObje
             // 2. Let p be MakeArgSetter(name, env).
             // 3. Perform map.[[DefineOwnProperty]](! ToString(𝔽(index)), PropertyDescriptor { [[Set]]: p, [[Get]]: g, [[Enumerable]]: false, [[Configurable]]: true }).
             object->parameter_map().define_native_accessor(
-                String::number(index),
+                PropertyName { index },
                 [&environment, name](VM&, GlobalObject& global_object_getter) -> Value {
                     return environment.get_binding_value(global_object_getter, name, false);
                 },