When Jeff Sessions was selected to lead as Attorney General, I was hopeful that he would make defunding sanctuary cities a priority. I’m pleased to report that some of last week’s policy discussion in Washington focused on this issue.

Sanctuary cities are municipalities that have implemented policies designed to help illegal immigrants avoid deportation. For instance, the city of San Francisco prohibits its police force from complying with U.S. Immigration and Customs Enforcement (ICE) agents by denying them access to interview incarcerated immigrants to determine legal status. ICE depends on cooperation from state and local authorities, and sanctuary city policies greatly hinder their ability to enforce our immigration laws.

Sanctuary cities are magnets for illegal immigrants, including some dangerous people with criminal records. There are more than 140 jurisdictions and six states actively obstructing enforcement of federal immigration laws with sanctuary policies. This practice puts Americans at risk, and I believe the federal government should do all it can to discourage it.

When I joined the Judiciary Committee, I made it clear that addressing our nation’s illegal immigration problem is one of my top priorities. Last week, the Judiciary Committee’s Subcommittee on Immigration and Border Security held a hearing on restoring immigration enforcement, and the issue of sanctuary cities was discussed at length. Witnesses ranging from a local sheriff and policy experts to a retired judge testified about the real world effects of the Obama Administration’s relaxed enforcement of immigration laws. Judiciary Committee Chairman Bob Goodlatte (R-Va.) referred to it as the “systematic dismantling of immigration enforcement infrastructure,” and he’s right.

In November 2014, as part of his executive actions on immigration, President Obama suspended the Secure Communities program. This was a successful initiative that allowed the Department of Homeland Security and the Federal Bureau of Investigation to work together to identify and deport illegal immigrants, thus prioritizing the removal of dangerous criminals.

These mistakes are being reversed. Just last week, Attorney General Jeff Sessions announced that sanctuary cities will no longer be eligible to receive grants from the Department of Justice. This was a good move. Cities, counties, and states that refuse to cooperate with federal agencies to enforce the laws of this country should not be rewarded with taxpayer dollars intended to facilitate law and order.

Our immigration system is broken and needs to be reformed, but border security must come first. When talking about this issue, I often use the analogy of a leaky house. If a leak in your roof is filling your house with water, would you replace the carpet first? Of course not, because first you need to stop the leak. In the same way, before we consider meaningful reforms to our immigration laws, we first must halt the flood of illegal immigrants across our border.

With the full support of the White House and Congress, Attorney General Sessions is working to fix the leak. Sanctuary cities have been put on notice: the federal government will no longer tolerate their flagrant disregard for our laws.

I look forward to working on solutions to fix our broken immigration system, and I’m excited that my new role on the Judiciary Committee gives me the opportunity to support Attorney General Jeff Sessions.

Martha Roby represents Alabama’s Second Congressional District. She lives in Montgomery, Alabama with her husband Riley and their two children.