Can't override GetHashCode (cannot change return type when overriding method int UnityEngine.Object.GetHashCode")

Hello, in my MonoBehaviour script i need to override GetHashCode. But whenever I do, I get the error cannot change return type when overriding method int UnityEngine.Object.GetHashCode" (Isn’t GetHashCode located inside the System namespace?)

My overriding:

public override int GetHashCode()
{
	return index.GetHashCode();
}

The error no longer exists if I remove the using UnityEngine header from the top.
I tried to explicitly tell it what to override, it didn’t work.

What’s going on here, how can I override GetHashCode here?

Thanks.

EDIT: I tried a brand new empty class, same result.

using UnityEngine;

public class Entry : MonoBehaviour
{
   public override int GetHashCode()
   {
	return base.GetHashCode();
   }
}

I also tried it in another project, it didn’t work.

As ArkaneX said, it’s working fine no problem. I’m sorry for the confusion, my original code turned out to be working fine, but it was a false Resharper error all along! I got a successful build even though R# is saying that there’s an error. I should never trust R# by its own without building.