diff --git a/PRIVATE b/PRIVATE
index 283c7567f..f60209558 160000
--- a/PRIVATE
+++ b/PRIVATE
@@ -1 +1 @@
-Subproject commit 283c7567f1e4f6f1893cb5b5efdbbda1682f7533
+Subproject commit f602095584e1d8c4f96e5746d6a199bd3bc029c3
diff --git a/src/IO.f90 b/src/IO.f90
index 8973860c2..c121cc65e 100644
--- a/src/IO.f90
+++ b/src/IO.f90
@@ -32,8 +32,7 @@ module IO
     IO_intValue, &
     IO_lc, &
     IO_error, &
-    IO_warning, &
-    IO_intOut
+    IO_warning
 #if defined(Marc4DAMASK) || defined(Abaqus)
   public :: &
     IO_open_inputFile, &
@@ -542,26 +541,6 @@ pure function IO_lc(string)
 end function IO_lc
 
 
-!--------------------------------------------------------------------------------------------------
-!> @brief returns format string for integer values without leading zeros
-!> @details deprecated, use '(i0)' format specifier
-!--------------------------------------------------------------------------------------------------
-pure function IO_intOut(intToPrint)
-
-  integer, intent(in) :: intToPrint
-  character(len=41)   :: IO_intOut
-  integer             :: N_digits
-  character(len=19)   :: width                                                                      ! maximum digits for 64 bit integer
-  character(len=20)   :: min_width                                                                  ! longer for negative values
-
-  N_digits =  1 + int(log10(real(max(abs(intToPrint),1))))
-  write(width, '(I19.19)') N_digits
-  write(min_width, '(I20.20)') N_digits + merge(1,0,intToPrint < 0)
-  IO_intOut = 'I'//trim(min_width)//'.'//trim(width)
-
-end function IO_intOut
-
-
 !--------------------------------------------------------------------------------------------------
 !> @brief write error statements to standard out and terminate the Marc/spectral run with exit #9xxx
 !> in ABAQUS either time step is reduced or execution terminated
diff --git a/src/grid/grid_mech_FEM.f90 b/src/grid/grid_mech_FEM.f90
index f6074fee9..a34d880f7 100644
--- a/src/grid/grid_mech_FEM.f90
+++ b/src/grid/grid_mech_FEM.f90
@@ -476,8 +476,7 @@ subroutine formResidual(da_local,x_local, &
 ! begin of new iteration
   newIteration: if (totalIter <= PETScIter) then
     totalIter = totalIter + 1
-    write(6,'(1x,a,3(a,'//IO_intOut(itmax)//'))') &
-            trim(incInfo), ' @ Iteration ', itmin, '≤',totalIter+1, '≤', itmax
+    write(6,'(1x,a,3(a,i0))') trim(incInfo), ' @ Iteration ', itmin, '≤',totalIter+1, '≤', itmax
     if (iand(debug_level(debug_spectral),debug_spectralRotation) /= 0) &
       write(6,'(/,a,/,3(3(f12.7,1x)/))',advance='no') &
               ' deformation gradient aim (lab) =', transpose(params%rotation_BC%rotTensor2(F_aim,active=.true.))
diff --git a/src/grid/grid_mech_spectral_basic.f90 b/src/grid/grid_mech_spectral_basic.f90
index fb69427e3..f05f9bc93 100644
--- a/src/grid/grid_mech_spectral_basic.f90
+++ b/src/grid/grid_mech_spectral_basic.f90
@@ -440,8 +440,7 @@ subroutine formResidual(in, F, &
 ! begin of new iteration
   newIteration: if (totalIter <= PETScIter) then
     totalIter = totalIter + 1
-    write(6,'(1x,a,3(a,'//IO_intOut(itmax)//'))') &
-            trim(incInfo), ' @ Iteration ', itmin, '≤',totalIter, '≤', itmax
+    write(6,'(1x,a,3(a,i0))') trim(incInfo), ' @ Iteration ', itmin, '≤',totalIter, '≤', itmax
     if (iand(debug_level(debug_spectral),debug_spectralRotation) /= 0) &
       write(6,'(/,a,/,3(3(f12.7,1x)/))',advance='no') &
               ' deformation gradient aim (lab) =', transpose(params%rotation_BC%rotTensor2(F_aim,active=.true.))
diff --git a/src/grid/grid_mech_spectral_polarisation.f90 b/src/grid/grid_mech_spectral_polarisation.f90
index ed2e0e1a9..33c3e4e72 100644
--- a/src/grid/grid_mech_spectral_polarisation.f90
+++ b/src/grid/grid_mech_spectral_polarisation.f90
@@ -509,8 +509,7 @@ subroutine formResidual(in, FandF_tau, &
 ! begin of new iteration
   newIteration: if (totalIter <= PETScIter) then
     totalIter = totalIter + 1
-    write(6,'(1x,a,3(a,'//IO_intOut(itmax)//'))') &
-            trim(incInfo), ' @ Iteration ', itmin, '≤',totalIter, '≤', itmax
+    write(6,'(1x,a,3(a,i0))') trim(incInfo), ' @ Iteration ', itmin, '≤',totalIter, '≤', itmax
     if (iand(debug_level(debug_spectral),debug_spectralRotation) /= 0) &
       write(6,'(/,a,/,3(3(f12.7,1x)/))',advance='no') &
               ' deformation gradient aim (lab) =', transpose(params%rotation_BC%rotTensor2(F_aim,active=.true.))