Optional parameters in managed C++/CLI methods

How can I declare a managed method in C++/CLI that has an optional parameter when used from C#?

I've decorated the parameter with both an Optional and a DefaultParameterValue attribute (see: How default parameter values are encoded), but only the Optional attribute seems to be honored.

C++/CLI:

public ref class MyClass1
{
 public:
  MyClass1([System::Runtime::InteropServices::Optional]
           [System::Runtime::InteropServices::DefaultParameterValue(2)]
           int myParam1)                                            ↑
  {
    System::Console::WriteLine(myParam1);
  }
};

C#:

var myInstance1 = new MyClass1();  // compiles and runs

Output:

0

Expected Output:

2

Visual C# IntelliSense:

MyClass1.MyClass1([int myParam1 = 0]);  // wrong default value
                                  ↑

Edit: A closer look with a disassembler reveals that the C++/CLI compiler does indeed not generate the required .param [1] = int32(2) directive. The IL code shown by Reflector is wrong.

Reflector:

.method public hidebysig specialname rtspecialname instance void .ctor([opt] int32 myParam1) cil managed
{
    .param [1] = int32(2)  // bug
    ...

ILDASM:

.method public hidebysig specialname rtspecialname instance void .ctor([opt] int32 myParam1) cil