Children born in the UK

Hi all,
I am a current Tier 2 General visa holder that is valid until July 2016. I will be applying for an extension by June 2016.
My wife is with me in the UK as a dependant to my visa.
We have a child together that was born last year in the UK and our names are on the birth certificate. I have not added my child as my dependant on my visa. I know our child will need a visa if travelling outside the UK but we don't plan to travel outside the UK until next year September.
Does anyone know if I may have any issue if by June 2016 when I plan to extend my visa as well as my wife, I also include our child at that point? i.e. our child won't have had any visa at the point of the visa extension

Should be okay.

Thanks Vinny,
Do you know of any documentation where I can find this information?

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