The House Ways and Means Committee is set to do its part this week in marking up the Tax Cut and Jobs Act, the long overdue overhaul of the broken tax code. It’s now 31 years since Congress last passed tax reform and the code is a complicated mess: full of distortions, facing a narrowing tax base, and plagued by higher than necessary marginal rates.

It’s apparent the code is a drag on economic growth and reform is needed badly. But as lawmakers put the final touches on the legislation, they should be cautious about one provision in particular that may violate international trade rules.