Specify certain properties of a type

I am trying to initialize objects for tests purposes. After initializing an object, I want to assert that all properties whose underlying type is a value type have a value that is not the default value of the property's type, with certain exceptions. I am not trying to recurse into sub-objects. For this purpose, I have the following:

    public static void NoValueTypedPropertyHasDefaultValue<T>(this T t, params string[] exceptions)
        where T: class
    {
        foreach (var property in typeof(T).GetProperties())
        {
            var propertyType = property.PropertyType;
            if (propertyType.IsValueType && !exceptions.Any(x => x == property.Name))
            {
                var defaultValue = Activator.CreateInstance(propertyType);
                object actualValue = property.GetValue(t);
                Assert.NotEqual(defaultValue, actualValue);
            }
        }
    }

Provided that everything has a parameterless constructor, it works. I'm not thrilled with the way I'm passing in strings for the exceptions. Is there a better way to do that?