ERROR: Invalid domain for site key when using captcha v2 with original site key

Good afternoon, I am trying to use reCaptcha v2 (No Captcha) with the original sitekey we have, and I'm getting the error ERROR: Invalid domain for site key Can I not use the original key for the new reCaptcha v2? Thanks! ~Geoff -- You received this message because you are subscribed to the Google Groups "reCAPTCHA" group. To unsubscribe from this group and stop receiving emails from it, send an email to recaptcha+unsubscribe@googlegroups.com. To post to this group, send email to recaptcha@googlegroups.com. Visit this group at http://bit.ly/1dkFnYd. For more options, visit http://bit.ly/P65DvS.