Minor league umpires are going to join a larger union.

The Association of Minor League Umpires (AMLU) passed a measure by a 91 percent to vote to join the Office and Professional Employees International Union of the AFL-CIO. The new union will be called AMLU/OPEIU Guild 322, the number representing three balls, two strikes, two outs.

"Our affiliation with OPEIU is the next step in a progression toward improving the lives and working conditions of some of the hardest working and most underappreciated people in the game," AMLU President Shaun Francis said in a release. "We evaluated the pros and cons of affiliation with a variety of different unions and OPEIU was head and shoulders above the rest. OPEIU's size, diversity of membership in a wide range of industries, as well as the quality of staff made them a perfect fit for our group."

Umpires starting salary is $1,800 a month and they are paid only during the season—from the start of spring training in March until September. Much like many minor league ballplayers, umpires are forced to find temporary employment during the offseason.

"We're now looking to take the umpires to another level and secure rights and benefits afforded to other baseball professionals, including wage improvements, job security and better working conditions," Francis said. "We look forward to bringing OPEIU's talents and resources into the world of professional umpiring to make these goals possible."