Some U.S. companies are feeling growing pressure to raise wages as unemployment falls and workers become harder to find, the Federal Reserve said Wednesday, a potential sign of a long-awaited pickup in Americans’ pay.

The report, based on anecdotes in the Fed’s regional survey of economic conditions known as the beige book, suggests wage growth remains sluggish nationally. But it offered strong evidence that in some pockets, such as parts of the Midwest, northern California and New York, workers are gaining leverage and starting to see a boost in pay.

“Several Districts reported increasing wage pressures caused by labor market tightening,” the Fed said.