diff --git a/src/variables.f90 b/src/variables.f90
index bb3917716d1b767c97dceb664ee275588ecf2df8..f67446a4e0c8c04a23db5b2b52f267b84b353526 100644
--- a/src/variables.f90
+++ b/src/variables.f90
@@ -591,7 +591,7 @@ contains
        !complex_geometry
        nxraf=(nxm)*nraf
        if (.not.nclx) nxraf=nxraf+1
-       nyraf=(nym)*nraf
+       nyraf=(nym)*nraf+20
        if (.not.ncly) nyraf=nyraf+1
        nzraf=(nzm)*nraf
        if (.not.nclz) nzraf=nzraf+1