Warnings about risks in Switzerland’s property market were taken a notch higher, with the banking regulator calling for measures to curb overheating in parts of the market.

FINMA highlighted dangers within buy-to-let real restate and said the mortgage market was “too big to fail.”

The statement comes after months of warnings from the Swiss National Bank, which has sounded the alarm about loan-to-value and affordability risks for residential investment properties.

“We intervene when individual institutions take on excessive risks, but we believe this is not enough to counteract the generalized overheating trends we are currently seeing,” FINMA CEO Mark Branson said on Thursday.

He said problem could only be tackled via changes to regulation or self-regulation.