diff --git a/src/MNH/mode_mnh_zwork.f90 b/src/MNH/mode_mnh_zwork.f90
index 423c55e2cb2eedacfc8c583242a43fd3d6637430..6f6189054e54c9d747471f169e94b47fb8743662 100644
--- a/src/MNH/mode_mnh_zwork.f90
+++ b/src/MNH/mode_mnh_zwork.f90
@@ -1131,7 +1131,7 @@ CONTAINS
     IKB = KKB
     IKE = KKE
 
-    ISIZE = ( IIE - IIB + 1_MNHINT64 ) * ( IJE - IJB + 1_MNHINT64 ) * ( IIE - IIB + 1_MNHINT64 )
+    ISIZE = ( IIE - IIB + 1_MNHINT64 ) * ( IJE - IJB + 1_MNHINT64 ) * ( IKE - IKB + 1_MNHINT64 )
 
     NTOT_ALLOCSIZE_ZT3DFLAT = NTOT_ALLOCSIZE_ZT3DFLAT + ISIZE