The Oklahoma House approved a Republican bill on Thursday that would ban abortions after six weeks of pregnancy.

The law would take effect immediately, cutting off access for patients from Texas who have flooded into Oklahoma since a similar law passed there last fall.

Coming ahead of a highly-anticipated U.S. Supreme Court decision on abortion expected this summer, the Oklahoma measure shows that states are not waiting for the high court to overturn the landmark Roe v. Wade decision enshrining abortion rights before acting to restrict the procedure within their own borders.