Writing .di files duplicate storage

[simendsjo]

I'm writing here because I haven't been able to create a smaller example 
and I'm not sure what to search for in bugzilla.

DMD adds a storage identifier twice when writing .di files.
This is my code:
    ///
    static @property isGUIThread() {
        return cast(bool)IsGUIThread(false);
    }
And this is the generated .di file:
    static @property @property  isGUIThread()
{
return cast(bool)IsGUIThread(false);
}

I have several other static @property fields too, but this is the only 
one affected.

Is this issue already in bugzilla? Or do I have to try to reproduce it 
in a smaller testcase?