diff --git a/src/MNH/nhoa_coupln.f90 b/src/MNH/nhoa_coupln.f90
index f8ea30639b021065de23652e151303524f0644f4..072dfbeb3ca7aa64c133a8d0b2855e4a3d1fdea8 100644
--- a/src/MNH/nhoa_coupln.f90
+++ b/src/MNH/nhoa_coupln.f90
@@ -49,6 +49,7 @@ SUBROUTINE NHOA_COUPL_n(KDAD,PTSTEP,KMI,KTCOUNT,KKU)
 !!   JL Redelsperger 03/2021   Version 0 
 !!    MODIFICATIONS
 !!    -------------
+!  P. Wautelet 17/12/2021: bugfix: set IIU and IJU values
 !!-----------------------------------------------------------------------------
 !
 !*      0.   DECLARATIONS
@@ -98,17 +99,20 @@ CHARACTER(LEN=4)                    :: ZINIT_TYPE
 !---Coupled OA MesoNH----------------------------------------------------------------------------
 !*      0.   INITIALISATION
 !            --------------
+IIU = SIZE(XRHODJ,1)
+IJU = SIZE(XRHODJ,2)
+
 ! allocate flux local array
-ALLOCATE(ZCOUPTFL(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPUFL(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPVFL(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
+ALLOCATE(ZCOUPTFL(IIU,IJU))
+ALLOCATE(ZCOUPUFL(IIU,IJU))
+ALLOCATE(ZCOUPVFL(IIU,IJU))
 ! allocate sfc variable local array
-ALLOCATE(ZCOUPUA(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPVA(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPTA(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPUO(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPVO(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
-ALLOCATE(ZCOUPTO(SIZE(XRHODJ,1),SIZE(XRHODJ,2)))
+ALLOCATE(ZCOUPUA(IIU,IJU))
+ALLOCATE(ZCOUPVA(IIU,IJU))
+ALLOCATE(ZCOUPTA(IIU,IJU))
+ALLOCATE(ZCOUPUO(IIU,IJU))
+ALLOCATE(ZCOUPVO(IIU,IJU))
+ALLOCATE(ZCOUPTO(IIU,IJU))
 ! values in ocean sfc
 IKE=KKU-JPVEXT
 ZCOUPUO(:,:)= XUT(:,:,IKE)