Forget the glass ceiling — according to a new study by LeanIn.org and McKinsey, companies first need to address the “broken rung” if they want to help get more women into leadership positions.

LeanIn.org and McKinsey last week released the fifth annual Women in the Workplace study. According to the results, the “glass ceiling” — or the invisible barrier that prevents women from reaching senior leadership positions — is not our biggest obstacle. That would be the broken rung — in other words, that first step up to a manager position.

The study says this broken rung results in more women getting stuck at the entry level and fewer women becoming managers. As a result, there are significantly fewer women to advance to higher levels.

Other key findings from the study include:

• Women are less likely to be hired and promoted to manager. For every 100 men promoted and hired to manager, only 72 women are promoted and hired.

• Men hold 62% of manager-level positions, while women hold just 38%. The number of women decreases at every subsequent level.

• One-third of companies set gender representation targets for first-level manager roles, compared with 41% for senior levels of management.

So what’s the solution? It’s simple — promote more women into their first management position. If companies do that, and women are hired and promoted to manager at the same rate as men, the study says we can add 1 million more women to management in corporate America over the next five years.

Women in the Workplace is the largest study of the state of women in corporate America. Results of this year’s study are based on five years of data from almost 600 companies. Read the full report online.