Getter only property in C# record struct primary constructor

If I declare a struct like this:

public record struct MyStruct(bool MyValue);

and then look at the decompiled source, it looks like this:

public struct MyStruct : IEquatable<MyStruct>
{
    [CompilerGenerated]
    private bool <MyValue>k__BackingField;

    public bool MyValue
    {
        [IsReadOnly]
        [CompilerGenerated]
        get
        {
            return <MyValue>k__BackingField;
        }
        [CompilerGenerated]
        set
        {
            <MyValue>k__BackingField = value;
        }
    }

    public MyStruct(bool MyValue)
    {
        <MyValue>k__BackingField = myValue;
    }

<etc>

How do I prevent the compiler from adding the set to MyValue property?

I would expect that changing it to:

public record struct MyStruct(in bool myValue);

would indicate that I want it to be readonly but this doesn't seem to make a difference