diff --git a/base/newserial/psbn_mat_impl.f03 b/base/newserial/psbn_mat_impl.f03
new file mode 100644
index 00000000..0117c09d
--- /dev/null
+++ b/base/newserial/psbn_mat_impl.f03
@@ -0,0 +1,25 @@
+subroutine psbn_d_spcnv(a,b,info,type,mold,upd,dupl)
+  use psbn_d_mat_mod, psb_protect_name => psbn_d_spcnv
+  use psb_realloc_mod
+  use psb_sort_mod
+  type(psbn_d_sparse_mat), intent(in)    :: a
+  type(psbn_d_sparse_mat), intent(out)   :: b
+  integer, intent(out)                   :: info
+  integer,optional, intent(in)           :: dupl, upd
+  character(len=*), optional, intent(in) :: type
+  class(psbn_d_base_sparse_mat), intent(in), optional :: mold
+  
+end subroutine psbn_d_spcnv
+
+subroutine psbn_d_spcnv_ip(a,info,type,mold,dupl)
+  use psbn_d_mat_mod, psb_protect_name => psbn_d_spcnv_ip
+  use psb_realloc_mod
+  use psb_sort_mod
+  
+  type(psbn_d_sparse_mat), intent(inout)  :: a
+  integer, intent(out)                    :: info
+  integer,optional, intent(in)            :: dupl
+  character(len=*), optional, intent(in)  :: type
+  class(psbn_d_base_sparse_mat), intent(in), optional :: mold
+
+end subroutine psbn_d_spcnv_ip