Hi, I am still trying to figure out how to add support for MatNullSpace with fortran data types. As I said in a previous email, adding the statement type MatNullSpace PetscFortranAddr:: v end type MatNullSpace in include/finclude/ftn-custom/petscmatdef.h90 is not enough. Furthermore, if I remove the corresponding statement type Mat PetscFortranAddr:: v end type Mat for Mat, I can still compile code with a statement like Type(Mat) :: M It looks like the fortran data type for Mat is defined somewhere else, but I can't figure out where. Can anybody shine some light for me? Blaise -- Department of Mathematics and Center for Computation & Technology Louisiana State University, Baton Rouge, LA 70803, USA Tel. +1 (225) 578 1612, Fax +1 (225) 578 4276 http://www.math.lsu.edu/~bourdin