The U.S.’s record streak of job growth kept going in May, but the economy may be starting to flash some warning signs.

U.S. employers added 138,000 jobs in May, the Bureau of Labor Statistics reported Friday. That was down a bit from April and was modestly below economists’ expectations. But taken on its own, May’s job growth wasn’t bad: It represented the 80th straight month of gains, the longest such streak on record. The economy has added more than 16 million jobs since the labor market bottomed out in early 2010.

But dig deeper into the report and the picture gets uglier. Revisions to data from March and April wiped out a combined 66,000 jobs from those months’ tallies. The labor force shrank by more than 400,000 people in May as baby boomers retired and fewer Americans looked for work. And earnings growth, which showed signs of accelerating last year, seems to have leveled off at a rate of about 2.5 percent per year.

Then there is the retail sector. Retailers cut jobs in May for the fourth straight month (revisions erased what had previously looked like a small gain in April), and although the last two months’ declines have been modest, they come amid signs of broader upheaval in the industry. Brick-and-mortar stores are struggling to compete with Amazon and other online retailers; in recent months, analysts have begun talking openly about the possibility of a “retail apocalypse.” Over the past four months, non-store retailers (mostly online sellers) have added 12,500 jobs while the rest of the sector has cut 92,600. Department stores alone have cut 18,600 jobs in that period.

Retailers’ struggles still pale in comparison to the challenges they faced during the 2008-09 recession, when the industry cut more than a million jobs over two years. And it is possible that some stores want to hire but are struggling to find workers willing to accept retail wages at a time when jobs are relatively plentiful. But it is worth paying close attention to the industry’s direction; there are nearly 16 million retail jobs in the U.S. Manufacturing, which tends to get far more attention from politicians, employs 12 million people. (Manufacturers also cut jobs in May.)

Beyond retail, it is much too soon to declare the job market in trouble. Employers have added more than 2 million jobs in the past year, and a month or two of slow growth isn’t unusual. Moreover, some slowdown in hiring was probably inevitable as the unemployment rate falls and the pool of available workers begins to dry up. But unlike in March, when weak job growth was accompanied by a growing labor force, May’s report was disappointing across the board. It’s too soon to worry, but not too soon to start paying attention.

Here are a couple of other observations from Friday’s report:

Unemployment falls for the wrong reasons: The unemployment rate fell to 4.3 percent in May, its lowest level since 2001. That might sound like good news. It isn’t.

The government only considers people unemployed if they are actively looking for work. That means the unemployment rate can fall for good reasons (because unemployed workers found jobs) or bad ones (because they gave up looking for work). May’s drop in the unemployment rate was solidly in the second category. The labor force — everyone who is either working or actively looking for work — shrank by more than 400,000 people, and there were actually 233,000 fewer people working in May than in April. (These figures are based on a separate survey than the more widely reported job totals. They generally move in sync but can diverge over brief periods.) The participation rate, which measures the share of adults who are in the labor force, fell two-tenths of a point, its second straight monthly decline.

A one- or two-month drop in the labor force isn’t necessarily cause for alarm. The retirement of the baby-boom generation is putting huge downward pressure on the participation rate, even as the improving economy should be drawing Americans back to work. The two forces have more or less offset over the past year, with the participation rate bouncing around but not really moving either up or down.

The Fed: One big question following Friday’s report: Were May’s numbers weak enough that the Federal Reserve will delay raising interest rates? The Fed had been widely expected to raise rates at its meeting later this month in an effort to keep inflation in check as the economy improves. But weak job growth, combined with slowing inflation, could give policymakers pause.

Investors, however, still see a hike as likely. The falling unemployment rate, flat participation rate and slowing job growth could all be signs that the job market is nearing the point where it can’t get much better — what economists call “full employment.” If Fed policymakers believe that interpretation, or consider it likely, they would probably see that as an argument for continuing to raise rates to keep the economy from overheating.