diff --git a/MNH/get_halo.f90 b/MNH/get_halo.f90
index 23ad1d771b1984067e45264256915706c731b482..55b64ed7b8b9609253aeef55589acc3d2c443609 100644
--- a/MNH/get_halo.f90
+++ b/MNH/get_halo.f90
@@ -129,6 +129,9 @@ USE MODE_ll
 USE MODD_ARGSLIST_ll, ONLY : LIST_ll
 USE MODD_PARAMETERS, ONLY : JPHEXT
 !
+USE MODD_IO_ll,   ONLY : GSMONOPROC
+!
+!
 IMPLICIT NONE
 !
 REAL, DIMENSION(:,:,:)     :: PSRC    ! variable at t
@@ -144,8 +147,11 @@ INTEGER,SAVE :: IIU,IJU,IKU
 !
 !LOGICAL, SAVE                               :: GFIRST_GET_HALO_D = .TRUE.
 !
-NULLIFY( TZ_PSRC_ll)
 
+IF (GSMONOPROC) RETURN
+!
+NULLIFY( TZ_PSRC_ll)
+!
 IF (GFIRST_GET_HALO_D ) THEN 
    CALL GET_INDICE_ll(IIB,IJB,IIE,IJE)
    !