diff --git a/src/grid_mod.F90 b/src/grid_mod.F90
index c362ac29e199ab106e964b788c59993f16572978..719effe7f116cce087e250a70a99aab4db4f553d 100644
--- a/src/grid_mod.F90
+++ b/src/grid_mod.F90
@@ -525,7 +525,7 @@ CONTAINS
     ! Ghosts boundaries (depend on the order of z operators)
     IF(Nz .EQ. 1) THEN
       izgs = izs;     izge = ize;
-      zarray(izs) = 0; zarray_full(izs) = 0;
+      zarray(izs,:) = 0; zarray_full(izs) = 0;
     ELSEIF(Nz .GE. 4) THEN
       izgs = izs - 2; izge = ize + 2;
     ELSE