MADISON, Wis. (AP) — Wisconsin Democrats are challenging the paperwork Donald Trump’s preferred candidate for governor filed to get on the ballot in the GOP primary on technical grounds.

The state Democratic Party said Sunday that construction company co-owner Tim Michels’ failed to include his correct mailing address on the nominating forms, making thousands of signatures invalid. But Michels’ campaign dismissed the complaint as frivolous.

In a statement, Michels says Tony Evers and his insider allies are working to keep him from beating Evers in November, “They will not succeed. Moreover, none of this sideshow will distract our campaign from taking the fight directly to Tony Evers.”

State Democratic Party Chair Ben Wikler said the flaw in the paperwork means only 345 signatures Michels submitted are valid. Michels said the complaint shouldn’t keep him off the ballot.

Trump endorsed Michels’ campaign last week.