There's a sensible fix to a particularly thorny issue under Obamacare, two senators from opposite sides of the aisle argued in a Wall Street Journal op-ed piece on Thursday.

Changing the definition of a full-time worker by increasing the weekly minimum hours from 30 to 40 will help keep employers from slashing hours to avoid providing coverage, Democratic Sen. Joe Donnelly and Republican Sen. Susan Collins wrote.

The senators said they've heard from small businesses, school systems, and nonprofits that "are cutting employee hours and forgoing additional hiring" in an effort to comply with the Affordable Care Act.

Collins, of Maine, and Indiana's Donnelly wrote that they introduced the "Forty Hours is Full Time Act of 2013" to resolve this problem with the healthcare law. The senators' bill, introduced Wednesday, defines a full-time employee as working an average of 40 hours a week or 174 hours a month for full-time equivalents.

Under the existing Obamacare law, businesses with 50 or more employees must provide coverage to full-time workers — those who average 30 hours or more a week — or face a fine.

"The rule is causing a growing number of employers to cut the hours of their workers, and according to one study by the UC Berkeley Labor Center, at least 2.3 million workers are at risk," the senators wrote.

"... It is clear that the definition of a full-time employee under the Affordable Care Act is not encouraging the economy to grow and is reducing the take-home pay of more and more Americans."

The White House recently decided to delay by one year a key requirement, the employer mandate, which calls for larger employers to offer health coverage. "We were pleased," Donnelly and Collins stated.

"Employers and employees around the country need a more accurate and sensible definition of what is a full-time employee in the health law," they wrote. "The pocketbooks of American families are depending on it. ..."