Oci with old un cancelled indian passport. Dont have th certificate of naturalization

[mtreddy2004]

I would be grateful for any help.
My Indian passport expired 96 not yet cancelled , Now a citizen of the USA for more than 16 years , have travelled to India on visitor visa.
The certificate of naturalization I received more than 16 years ago is lost.
The old passport is proof of Indian nationality , and the american passport proof of US citizenship, do I still need certificate of naturalization ?
Any one else in my situation ?
Please reply
Thanking you
Mtreddy2004

[immihelp]

It is required.

Apply to get it replaced. /show-form/n-600