Zero2000 and Sekonic L-508

Hi,
I'm using Zero2000 pinhole camera that have a F/138 aperture size hole. I meter with Sekonic L-508 hand held meter.
My meter can read up to F/128.
What is the different between F/138 to F/128 in terms of exposure compensation? If I meter according to F/128 how much exposure do I need to add for F/138?

Thank you,
Nir.

Considering using a pinhole camera without an automatic shutter is a hit-and-miss in terms of accurate exposure anyway, I wouldn't bother at all about an F138 versus F128 F-stop difference...

I don't with my Zero Image pinhole, it is all part of the fun and charm of using a pinhole that you don't always get repeatable or fully accurate results!