diff --git a/base/internals/psi_crea_ovr_elem.f90 b/base/internals/psi_crea_ovr_elem.f90
index 978d2e60a..d15f68294 100644
--- a/base/internals/psi_crea_ovr_elem.f90
+++ b/base/internals/psi_crea_ovr_elem.f90
@@ -42,105 +42,107 @@
 !    desc_a   - type(psb_desc_type).       The communication descriptor.        
 !    info     - integer.                   return code.
 ! 
-subroutine psi_crea_ovr_elem(me,desc_overlap,ovr_elem,info)
-
-  use psi_mod, psb_protect_name => psi_crea_ovr_elem
-  use psb_realloc_mod
-  use psb_error_mod
-  use psb_penv_mod
-  use psb_serial_mod
-  implicit none
-
-  !     ...parameter arrays....      
-  integer(psb_ipk_), intent(in)               :: me, desc_overlap(:)
-  integer(psb_ipk_), allocatable, intent(out) :: ovr_elem(:,:)
-  integer(psb_ipk_), intent(out)              :: info
-
-  !     ...local scalars...
-  integer(psb_ipk_) :: i,pnt_new_elem,ret,j
-  integer(psb_ipk_) :: dim_ovr_elem
-  integer(psb_ipk_) :: pairtree(2)
-
-  !     ...external function...
-  integer(psb_ipk_) :: psi_exist_ovr_elem
-  external :: psi_exist_ovr_elem
-
-  integer(psb_ipk_) :: nel, ip, ix, iel, insize, err_act, iproc
-  integer(psb_ipk_), allocatable :: telem(:,:)
-
-  character(len=20)    :: name
-
-
-  info = psb_success_
-  name='psi_crea_ovr_elem'
-
-
-  if (allocated(ovr_elem)) then 
-    dim_ovr_elem = size(ovr_elem,1)
-  else
-    dim_ovr_elem = 0
-  endif
-
-
-  insize = size(desc_overlap)
-  insize = max(1,(insize+1)/2)
-  allocate(telem(insize,3),stat=info)
-  if (info /= psb_success_) then 
-    info = psb_err_alloc_dealloc_
-    call psb_errpush(info,name)
-    goto 9999
-  endif
-  i   = 1
-  nel = 0
-  do while (desc_overlap(i) /= -1)
-    !        ...loop over all procs of desc_overlap list....
-    iproc = desc_overlap(i)
-    i     = i+1
-    do j=1,desc_overlap(i)
-      nel = nel + 1 
-      telem(nel,1) = desc_overlap(i+j)
-      telem(nel,2) = 1
-      telem(nel,3) = iproc
+submodule (psi_i_mod) psi_crea_ovr_elem_impl_mod
+contains
+  subroutine psi_crea_ovr_elem(me,desc_overlap,ovr_elem,info)
+
+    use psb_realloc_mod
+    use psb_error_mod
+    use psb_penv_mod
+    use psb_serial_mod
+    implicit none
+
+    !     ...parameter arrays....      
+    integer(psb_ipk_), intent(in)               :: me, desc_overlap(:)
+    integer(psb_ipk_), allocatable, intent(out) :: ovr_elem(:,:)
+    integer(psb_ipk_), intent(out)              :: info
+
+    !     ...local scalars...
+    integer(psb_ipk_) :: i,pnt_new_elem,ret,j
+    integer(psb_ipk_) :: dim_ovr_elem
+    integer(psb_ipk_) :: pairtree(2)
+
+    !     ...external function...
+    integer(psb_ipk_) :: psi_exist_ovr_elem
+    external :: psi_exist_ovr_elem
+
+    integer(psb_ipk_) :: nel, ip, ix, iel, insize, err_act, iproc
+    integer(psb_ipk_), allocatable :: telem(:,:)
+
+    character(len=20)    :: name
+
+
+    info = psb_success_
+    name='psi_crea_ovr_elem'
+
+
+    if (allocated(ovr_elem)) then 
+      dim_ovr_elem = size(ovr_elem,1)
+    else
+      dim_ovr_elem = 0
+    endif
+
+
+    insize = size(desc_overlap)
+    insize = max(1,(insize+1)/2)
+    allocate(telem(insize,3),stat=info)
+    if (info /= psb_success_) then 
+      info = psb_err_alloc_dealloc_
+      call psb_errpush(info,name)
+      goto 9999
+    endif
+    i   = 1
+    nel = 0
+    do while (desc_overlap(i) /= -1)
+      !        ...loop over all procs of desc_overlap list....
+      iproc = desc_overlap(i)
+      i     = i+1
+      do j=1,desc_overlap(i)
+        nel = nel + 1 
+        telem(nel,1) = desc_overlap(i+j)
+        telem(nel,2) = 1
+        telem(nel,3) = iproc
+      enddo
+      i=i+2*desc_overlap(i)+2
     enddo
-    i=i+2*desc_overlap(i)+2
-  enddo
-
-  if (nel > 0) then 
-    call psb_msort(telem(1:nel,1),ix=telem(1:nel,3),flag=psb_sort_keep_idx_)
-
-    iel        = telem(1,1)
-    telem(1,2) = 2
-    telem(1,3) = min(me,telem(1,3))
-    ix = 1
-    ip = 2
-    do 
-      if (ip > nel) exit
-      if (telem(ip,1) == iel) then 
-        telem(ix,2) = telem(ix,2) + 1
-        telem(ix,3) = min(telem(ix,3),telem(ip,3))
-      else
-        ix = ix + 1
-        telem(ix,1) = telem(ip,1)
-        iel         = telem(ip,1)
-        telem(ix,2) = 2
-        telem(ix,3) = min(me,telem(ip,3))
-      end if
-      ip = ip + 1
-    end do
-  else
-    ix = 0
-  end if
-
-  nel = ix
-
-  call psb_realloc(nel,3,telem,info)
-  call psb_move_alloc(telem,ovr_elem,info) 
-
-  call psb_erractionrestore(err_act)
-  return
+
+    if (nel > 0) then 
+      call psb_msort(telem(1:nel,1),ix=telem(1:nel,3),flag=psb_sort_keep_idx_)
+
+      iel        = telem(1,1)
+      telem(1,2) = 2
+      telem(1,3) = min(me,telem(1,3))
+      ix = 1
+      ip = 2
+      do 
+        if (ip > nel) exit
+        if (telem(ip,1) == iel) then 
+          telem(ix,2) = telem(ix,2) + 1
+          telem(ix,3) = min(telem(ix,3),telem(ip,3))
+        else
+          ix = ix + 1
+          telem(ix,1) = telem(ip,1)
+          iel         = telem(ip,1)
+          telem(ix,2) = 2
+          telem(ix,3) = min(me,telem(ip,3))
+        end if
+        ip = ip + 1
+      end do
+    else
+      ix = 0
+    end if
+
+    nel = ix
+
+    call psb_realloc(nel,3,telem,info)
+    call psb_move_alloc(telem,ovr_elem,info) 
+
+    call psb_erractionrestore(err_act)
+    return
 
 9999 call psb_error_handler(err_act)
 
-  return
+    return
 
-end subroutine psi_crea_ovr_elem
+  end subroutine psi_crea_ovr_elem
+end submodule psi_crea_ovr_elem_impl_mod