diff --git a/base/serial/impl/psb_c_coo_impl.F90 b/base/serial/impl/psb_c_coo_impl.F90
index 830b7400..306aefd9 100644
--- a/base/serial/impl/psb_c_coo_impl.F90
+++ b/base/serial/impl/psb_c_coo_impl.F90
@@ -572,7 +572,7 @@ subroutine  psb_c_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -6012,7 +6012,7 @@ subroutine  psb_lc_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_c_csc_impl.f90 b/base/serial/impl/psb_c_csc_impl.f90
index 87d7e3dd..3e3aa9eb 100644
--- a/base/serial/impl/psb_c_csc_impl.f90
+++ b/base/serial/impl/psb_c_csc_impl.f90
@@ -2621,8 +2621,8 @@ subroutine  psb_c_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_ipk_,a%get_ncols())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -4461,8 +4461,8 @@ subroutine  psb_lc_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_lpk_,a%get_ncols())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_c_csr_impl.f90 b/base/serial/impl/psb_c_csr_impl.f90
index c8819ba3..de49a56f 100644
--- a/base/serial/impl/psb_c_csr_impl.f90
+++ b/base/serial/impl/psb_c_csr_impl.f90
@@ -2754,8 +2754,8 @@ subroutine  psb_c_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_ipk_,a%get_nrows())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
@@ -5029,8 +5029,8 @@ subroutine  psb_lc_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_lpk_,a%get_nrows())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
diff --git a/base/serial/impl/psb_d_coo_impl.F90 b/base/serial/impl/psb_d_coo_impl.F90
index 24b486e2..d8d241ed 100644
--- a/base/serial/impl/psb_d_coo_impl.F90
+++ b/base/serial/impl/psb_d_coo_impl.F90
@@ -572,7 +572,7 @@ subroutine  psb_d_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -6012,7 +6012,7 @@ subroutine  psb_ld_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_d_csc_impl.f90 b/base/serial/impl/psb_d_csc_impl.f90
index 4f10439b..a0e4be09 100644
--- a/base/serial/impl/psb_d_csc_impl.f90
+++ b/base/serial/impl/psb_d_csc_impl.f90
@@ -2621,8 +2621,8 @@ subroutine  psb_d_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_ipk_,a%get_ncols())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -4461,8 +4461,8 @@ subroutine  psb_ld_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_lpk_,a%get_ncols())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_d_csr_impl.f90 b/base/serial/impl/psb_d_csr_impl.f90
index 70821a9e..0cd58458 100644
--- a/base/serial/impl/psb_d_csr_impl.f90
+++ b/base/serial/impl/psb_d_csr_impl.f90
@@ -2754,8 +2754,8 @@ subroutine  psb_d_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_ipk_,a%get_nrows())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
@@ -5029,8 +5029,8 @@ subroutine  psb_ld_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_lpk_,a%get_nrows())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
diff --git a/base/serial/impl/psb_s_coo_impl.F90 b/base/serial/impl/psb_s_coo_impl.F90
index be4218de..7ddb20cb 100644
--- a/base/serial/impl/psb_s_coo_impl.F90
+++ b/base/serial/impl/psb_s_coo_impl.F90
@@ -572,7 +572,7 @@ subroutine  psb_s_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -6012,7 +6012,7 @@ subroutine  psb_ls_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_s_csc_impl.f90 b/base/serial/impl/psb_s_csc_impl.f90
index e52086d1..2711c2f8 100644
--- a/base/serial/impl/psb_s_csc_impl.f90
+++ b/base/serial/impl/psb_s_csc_impl.f90
@@ -2621,8 +2621,8 @@ subroutine  psb_s_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_ipk_,a%get_ncols())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -4461,8 +4461,8 @@ subroutine  psb_ls_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_lpk_,a%get_ncols())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_s_csr_impl.f90 b/base/serial/impl/psb_s_csr_impl.f90
index 65713f7b..ef24c4b3 100644
--- a/base/serial/impl/psb_s_csr_impl.f90
+++ b/base/serial/impl/psb_s_csr_impl.f90
@@ -2754,8 +2754,8 @@ subroutine  psb_s_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_ipk_,a%get_nrows())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
@@ -5029,8 +5029,8 @@ subroutine  psb_ls_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_lpk_,a%get_nrows())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
diff --git a/base/serial/impl/psb_z_coo_impl.F90 b/base/serial/impl/psb_z_coo_impl.F90
index 4f99cb5c..b9dd7e59 100644
--- a/base/serial/impl/psb_z_coo_impl.F90
+++ b/base/serial/impl/psb_z_coo_impl.F90
@@ -572,7 +572,7 @@ subroutine  psb_z_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -6012,7 +6012,7 @@ subroutine  psb_lz_coo_trim(a)
   call psb_erractionsave(err_act)
   info = psb_success_
   if (a%is_dev())   call a%sync()
-  nz  = a%get_nzeros()
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_z_csc_impl.f90 b/base/serial/impl/psb_z_csc_impl.f90
index 8b0ccc65..a2254035 100644
--- a/base/serial/impl/psb_z_csc_impl.f90
+++ b/base/serial/impl/psb_z_csc_impl.f90
@@ -2621,8 +2621,8 @@ subroutine  psb_z_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_ipk_,a%get_ncols())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
@@ -4461,8 +4461,8 @@ subroutine  psb_lz_csc_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  n   = a%get_ncols()
-  nz  = a%get_nzeros()
+  n   = max(1_psb_lpk_,a%get_ncols())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(n+1,a%icp,info)
   if (info == psb_success_) call psb_realloc(nz,a%ia,info)
   if (info == psb_success_) call psb_realloc(nz,a%val,info)
diff --git a/base/serial/impl/psb_z_csr_impl.f90 b/base/serial/impl/psb_z_csr_impl.f90
index a7f41138..29cf9e4e 100644
--- a/base/serial/impl/psb_z_csr_impl.f90
+++ b/base/serial/impl/psb_z_csr_impl.f90
@@ -2754,8 +2754,8 @@ subroutine  psb_z_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_ipk_,a%get_nrows())
+  nz  = max(1_psb_ipk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)
@@ -5029,8 +5029,8 @@ subroutine  psb_lz_csr_trim(a)
 
   call psb_erractionsave(err_act)
   info = psb_success_
-  m   = a%get_nrows()
-  nz  = a%get_nzeros()
+  m   = max(1_psb_lpk_,a%get_nrows())
+  nz  = max(1_psb_lpk_,a%get_nzeros())
   if (info == psb_success_) call psb_realloc(m+1,a%irp,info)
 
   if (info == psb_success_) call psb_realloc(nz,a%ja,info)