NEW YORK (CNNMoney) - Not a Prime member? You'll have to spend more on Amazon before free shipping kicks in.
The e-commerce giant hiked the minimum required for free shipping for non-Prime members to $49 from $35 on eligible items -- a 40% increase. It's unclear when the change took effect.
Amazon orders that include at least $25 in qualified books also ship free.
Prime members are not affected by the change.
Less than three years ago, Amazon raised the minimum to $35, after years of a $25 minimum price to qualify for free shipping.
The move is likely intended to entice more shoppers to purchase Prime memberships. The program costs $99 a year and includes free two-day shipping on eligible items along with unlimited streaming of movies, TV shows and music.
Last year, Prime memberships worldwide increased 51% -- with a 47% bump in the U.S.
A recent report from Consumer Intelligence Research Partners estimated that almost half of households in the U.S. have a Prime account.
The Seattle-based company reported a record profit in the fourth quarter of 2015 of $482 million, with part of its retail success coming from the membership program.
The company did not immediately return a request for comment on the change Monday morning.