force to use cholmod

I have theoretically symmetric sparse matrix which is not numerically symmetric.

After assemble my matrix, I have

 max(max(abs(A-A')))=1.e-16

which is negligible.

However, matlab does not consider this matrix as symmetric matrix. Hence, matlab does not use CHOLMOD to solve this matrix.

Of course, I can do

 A=(A+A')/2

or other thing to make A symmetric.

However, I don't want to do this because it takes quite long time to transpose and take sum.

Is there any other way to force matlab to use CHOLMOD?