Your morning coffee may get a little slower.

Starbucks (SBUX) is telling its baristas to slow down the preparation of drinks in order to counter the image of a hot drinks assembly line. Under new guidelines for stores in the U.S. and Canada, baristas will be allowed to work on no more than two drinks at any time, The Wall Street Journal said.

Slower drinks could mean longer lines.

"While I'm blending a frappuccino, it doesn't make sense to stand there and wait for the blender to finish running, because I could be making an iced tea at the same time," Tyler Swain, a barista in Omaha, Neb., told The Wall Street Journal. Swain's store has not yet adopted the new measures.

Starbucks says the new rules, which will be enforced by next month, will help make stores more efficient and improve the quality of the drinks. Customers have noted that Starbucks espresso is "average" and that the quality of preparation is inconsistent.

Other new rules include rinsing pitchers after each use and only using one espresso machine instead of two.

The company has worked aggressively to improve its business in a weak economy, closing underperforming stores, boosting loyalty-card perks and introducing new varieties of instant coffee.

Earnings rose 37% in the quarter that ended June 27.