mocha jsverify shrink failure

test.js

jsc = require('jsverify');

(function() {
  arbitraryPositiveInteger = jsc.nat.smap(
    function (n) {return n + 1;},
    function (n) {return n - 1;}
  );

  describe('test with arbitrary array and two smapped arbitrary params',
      function() {
      jsc.property('does not shrink',
        jsc.array(jsc.nat), arbitraryPositiveInteger, arbitraryPositiveInteger,
        function(array, int1, int2) {
          return false; // fail
        }
      );
    });
})();