Falling mortgage rates are spurring a surge in U.S. homeowners seeking to refinance their loans to lock in lower payments.

A gauge of mortgage refinancing volume rose 5% last week to the highest level since June 2013, according to a Mortgage Bankers Association report Wednesday that also showed such transactions accounted for 65.5% of all applications, the most in almost five years.

The average contract rate on a 30-year mortgage ticked up to 3.72%, rising 1 basis point from the prior week’s three-year low. It was the first increase in seven weeks. Applications for loans to purchase homes fell for a second week after touching an 11-year high.

Home borrowing costs have eased in recent weeks as Treasury yields slumped on growing concern about how much the spread of the coronavirus will weigh on China’s economy. The 30-year Treasury yield edged up last week but remains near a four-month low.

“Last month was the strongest January for purchase applications since 2009, which is perhaps a sign that mild weather brought out prospective buyers earlier than normal,” Joel Kan, MBA’s associate vice president of economic and industry forecasting, said in a statement.