Function quat2angle does not account for singularities

It seems that the function quat2angle does not account for the singularity that occurs when the second Euler angle is +/- 90 deg (for a ZYX rotation sequence). Example code:

u = deg2rad([90 -90 15]);
q = angle2quat(u(1),u(2),u(3));
[u1 u2 u3] = quat2angle(q);
u_new = rad2deg([u1 u2 u3])

u_new =

  104.0362  -90.0000   18.4349

Is there a fix for this?