It is usually assumed that proteins with disordered regions are less stable than proteins with a more rigid arrangement of their atoms. In order to test whether this proposition holds true for peptides as well, we selected a peptide known to have a stable three-dimensional structure for its first seven amino acids (with the last four being highly disordered), and followed its folding and unfolding events using all-atom molecular dynamics simulations. We simulated both the complete peptide, and two shortened form of the peptide missing the last four or last two (disordered) residues. Comparison between the results obtained from those simulations shows that the peptide containing the disordered regions is actually more stable (for its folded part) than the peptide lacking them. Our results have applications in the ab initio design of peptides with stable three-dimensional structures.