U.S. Senator Chuck Schumer has a gripe with a legal and well-known process at Canada’s border that he says is leading to longer lines and backups at the U.S. border.

Schumer is urging Canada to end “flagpoling,” which allows non-Canadian citizens to quickly get their work permits by briefly entering the U.S. and then returning to Canada.

Speaking at a press conference at the Rainbow Bridge earlier this week, Schumer said the process is “increasing traffic and wait times here at the border, hampering smooth commerce between our nations, (and) hampering tourism.”