The clock is ticking for roughly 12,000 Chinese immigrants in Taiwan, who have until Monday to prove they’ve given up their household registration in China.

Failure to meet the deadline could mean losing residency rights, according to Taiwan’s government — and possible deportation.

Taiwan’s Mainland Affairs Council announced the June 30 deadline in April amid a wave of national security measures after President Lai Ching-te labeled China a “hostile foreign force.” Lai’s administration wants to strengthen defenses against Chinese influence, but many immigrants worry it could come at a personal cost.