A stubborn pay gap continues between male and female nurses, despite the fact that women continue to dominate the ranks of the profession, according to new research.

That was one of the key takeaways from a new study released Monday by Nurse.com and its parent company, OnCourse Learning. Polling some 4,500 RNs from across the country, researchers found that male nurses earned an average salary of nearly $79,700. That’s more than $6,000 greater that the roughly $73,100 earned by their female counterparts. Men make up only about 12% of the nursing workforce.

Male nurses are collecting more, even when age, experience and education are taken into account, those involved note.

“Based on this survey, it seems clear men are being paid significantly more than women in the profession, doing comparable work,” Brent MacWilliams, Ph.D., RN, president of the American Association for Men in Nursing, said in a press release. “I would call on employers to assess their current workforce for gender gaps and raise salaries to create parity.”

One possible reason for the disparity, researchers said, is negotiation tactics. About 43% of men surveyed said they negotiated their pay “most of the time or always,” compared to just 34% of women.