Naughty Fish Capacitor 16V OK?

[dobrien9]

Hey all.  I'm in the process of building a Naughty Fish and I realized when populating the board that I only had a 16V 220mf Cap in position C11.  All caps are specified as 25V minimum.  I don't really want to place an order for the 25V cap when I don't need anything else.  Is this particular cap a real concern at 16V?  I'm not sure how it's functioning in the circuit.  Looks like it might be a power supply filter or something.  Any suggestions or advice would be appreciated. 

Thanks!

[RDL68]

Edit: Precautionary 'replace it' post edited out...

[madbean]

16v is okay here since it is only decoupling the 9v input. 100uF is also okay.