Smart companies have many reasons to root out any conflicts of interest between their employees and the organization. An employee helping a competitor, for example, is cause for serious concern and action. But after a recent ruling from the National Labor Relations Board, companies will have to be very careful about how they draft and structure bans on conflicts of interest.

The NLRB has ruled that an Alaska hotel’s employee handbook stepped over a legal line when it used language that prohibited conflicts of interest and disciplined employees accordingly. The board’s decision indicates that companies that want to outlaw these conflicts need to avoid making rules in terms the board would consider overly broad.