According to the IRS you will need to amend ... there have been no new instructions issued yet to include an exception to the standing regulations for taxpayers who filed a "stimulus registration" return by mistake. See tax topic 308 : https://www.irs.gov/taxtopics/tc308
If you discover an error after filing your return, you may need to amend your return. The IRS may correct mathematical or clerical errors on a return and may accept returns without certain required forms or schedules. In these instances, there's no need to amend your return. However, do file an amended return if there's a change in your filing status, income, deductions, or credits. Use Form 1040-X, Amended U.S. Individual Income Tax Return (PDF) to correct a previously filed Form 1040 (PDF), Form 1040A (PDF), Form 1040EZ (PDF), Form 1040-NR (PDF), Form 1040-NR-EZ (PDF), or to change amounts previously adjusted by the IRS.
