diff --git a/Userland/Libraries/LibJS/Runtime/Array.cpp b/Userland/Libraries/LibJS/Runtime/Array.cpp
index 0f893068f0..6d88ccf103 100644
--- a/Userland/Libraries/LibJS/Runtime/Array.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Array.cpp
@@ -17,7 +17,7 @@
 namespace JS {
 
 // 10.4.2.2 ArrayCreate ( length [ , proto ] ), https://tc39.es/ecma262/#sec-arraycreate
-ThrowCompletionOr<Array*> Array::create(GlobalObject& global_object, size_t length, Object* prototype)
+ThrowCompletionOr<Array*> Array::create(GlobalObject& global_object, u64 length, Object* prototype)
 {
     auto& vm = global_object.vm();
 
diff --git a/Userland/Libraries/LibJS/Runtime/Array.h b/Userland/Libraries/LibJS/Runtime/Array.h
index a3d793d05d..7886ac3c83 100644
--- a/Userland/Libraries/LibJS/Runtime/Array.h
+++ b/Userland/Libraries/LibJS/Runtime/Array.h
@@ -21,7 +21,7 @@ class Array : public Object {
     JS_OBJECT(Array, Object);
 
 public:
-    static ThrowCompletionOr<Array*> create(GlobalObject&, size_t length, Object* prototype = nullptr);
+    static ThrowCompletionOr<Array*> create(GlobalObject&, u64 length, Object* prototype = nullptr);
     static Array* create_from(GlobalObject&, Vector<Value> const&);
     // Non-standard but equivalent to CreateArrayFromList.
     template<typename T>