Be warned if you changed your political party -- like thousands of Oregon voters -- right before the state's April 26 deadline.

Elections officials say the ballot that hit your mailbox this week is almost certainly the wrong one -- full of races from the party you switched from, and not the one you switched to. That's likely true for anyone who submitted a change after April 13.

But don't fret about losing your chance to vote. Updated ballots, correctly assembled, are already on the way, officials promise.

If you haven't sent back the first one (most Oregonians tend to wait), then all you have to do is sit tight, wait for the replacement and vote before May 17 like you normally would. Even you voted promptly, officials say, fill out the new ballot and send that one in, too. That's the one they'll count.

"There's nothing wrong. It's OK to have two ballots," said Molly Woon, spokeswoman for the Oregon Secretary of State Jeanne Atkins, saying concerned voters should call their local elections office. "But you won't get to vote twice."

Tim Scott, Multnomah County's elections officer, said it's the price of being prepared. To make sure 450,000 or so ballots go out on time, county officials start printing and assembling them days before the deadline to make changes.

"There's not a lot of downtime," Scott said. "It's a really labor intensive, time-consuming process."

Normally, those preparations aren't a problem. Few people switch. But this hasn't been any old Oregon primary.

Bernie Sanders has so far refused to cede the Democrats' presidential nod to Hillary Clinton. And Donald Trump is still working furiously to put away Ted Cruz and John Kasich on the Republican ticket.

Tens of thousands of Oregon voters have switched parties -- or joined one for the first time -- in hopes of getting in on the action. Beyond those changes, some 100,000 new voters also joined the rolls this year.

Asked whether county clerks started printing ballots too early, given the well-known interest, Scott said waiting for changes might have kept all the other thousands of registered voters from receiving their ballots on time.

"If you think about it," he said, "it wasn't so early."

Scott also explained the protections meant to keep ballots from being double-counted. Because each ballot has a unique barcode, once a second ballot is created for a voter, elections officials can deactivate their original.

Those ballots, if they're sent back and scanned, will then be set aside until election day. From there, officials will check each one to see if a second ballot was sent in its place.

If it was, then the original ballots will be destroyed. If not, Scott said, officials will tally only the nonpartisan votes, for races including city councils, ballot measures and judicial contests.

"We can't count votes on offices for a party the person's not part of," Scott said.

On Friday, Atkins' Twitter account noted the confusion, but offered advice in the form of a haiku:

Two ballots? Don't fret.

Vote the second ballot, please.

Safeguards are in place.

-- Denis C. Theriault

503-221-8430; @TheriaultPDX