Prices at the wholesale level climbed 0.4% in October and 2.8% over the past year, the biggest annual jump in more than five years and a sign that an improving economy may finally be reviving inflationary pressures.

The Labor Department says last month’s increase in the producer price index, which measures inflation pressures before they reach the consumer, matched the 0.4% rise in September. The uptick from October 2016 was the biggest since February 2012. The 12-month increase was driven by a 7.6% jump in energy prices.

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But energy prices were unchanged from September to October. Food prices rose 0.5% in October, most since June. Excluding the volatile food and energy sectors, wholesale prices rose 0.3% in October from September.

“The above consensus readings on today’s prices does lend some support to our on-consensus call for a 0.2% core CPI reading tomorrow, given that it’s been tracking softer than that recently,” says Royce Mendes of CIBC Economics, in a release. “Still, markets will wait for tomorow’s data to make a judgement on whether inflation is perking back up.”

Producer prices rose faster than economists had expected in October. Since the recession, inflation has come in consistently below the Federal Reserve’s 2% annual target. But many economists expect price pressures to rise as the economy improves. Economic growth has come in at or better than a healthy 3% annual rate in each of the last two quarters; and unemployment has fallen to 4.1%, the lowest level in almost 17 years.