Bloomberg said Scandinavia’s mortgage model is adding risk to the region’s economies as too few homeowners pay down their debt. Moody’s Investors Service now casts doubts over Nordic havens amid housing risks.

Oscar Heemskerk, vice president and senior credit officer at Moody’s, warns that consumers in Sweden and Denmark rely too much on the loans.

“House prices have continued to increase a lot in Sweden, and in Norway particularly, raising questions whether that can continue forever,” Heemskerk told Bloomberg. “What we have seen internationally, time and time again, is that if something goes up, ultimately there will be some corrections.”

The International Monetary Fund is urging Sweden to impose minimum amortization rules to prevent a property bubble.