diff --git a/src/LIB/SURCOUCHE/src/mode_io.f90 b/src/LIB/SURCOUCHE/src/mode_io.f90
index 0d6f357a252227494be4ffca5190917528e12ab0..430fe98de8f8718f65fc861d89273bd737872218 100644
--- a/src/LIB/SURCOUCHE/src/mode_io.f90
+++ b/src/LIB/SURCOUCHE/src/mode_io.f90
@@ -26,6 +26,7 @@
 !     Philippe Wautelet: 21/01/2019: add LIO_ALLOW_NO_BACKUP and LIO_NO_WRITE to modd_io_ll to allow
 !                                    to disable writes (for bench purposes)
 !  P. Wautelet 04/04/2019: force write on stderr for all processes in print_msg if abort
+!  P. Wautelet 02/07/2019: flush messages also for files opened with newunit (logical unit can be negative)
 !
 MODULE MODE_IO_ll
 
@@ -859,9 +860,9 @@ IF (KVERB<=IABORTLEVEL) THEN
 #if 0
   !Problem: loop dependency between MODE_MSG and MODE_FM (IO_FILE_CLOSE_ll call PRINT_MSG)
   NIO_VERB = 0 !To not get further messages (ABORT should be the last for readability)
-  IF (ILU>0) CALL IO_FILE_CLOSE_ll(TFILE_OUTPUTLISTING) !To flush it
+  IF ( ILU /= -1 ) CALL IO_FILE_CLOSE_ll(TFILE_OUTPUTLISTING) !To flush it
 #else
-  IF (ILU>0) FLUSH(UNIT=ILU) !OK in F2003
+  IF ( ILU /= -1 ) FLUSH(UNIT=ILU) !OK in F2003
   IF (ASSOCIATED(TLUOUT0)) FLUSH(UNIT=TLUOUT0%NLU)
 #endif
   !Add a sleep to ensure that the process(es) that have to write to stderr and to file