diff --git a/src/collision_mod.F90 b/src/collision_mod.F90
index c2286157c031a6fe187c95b2420a9d03a5b3789d..2209615acf896e4d903d8878f1742ffbd879c670 100644
--- a/src/collision_mod.F90
+++ b/src/collision_mod.F90
@@ -270,7 +270,7 @@ CONTAINS
     INTEGER,     INTENT(IN) :: ip0_, ip1_, ip2_,jmax_
     INTEGER,     DIMENSION(ips_:ipe_), INTENT(IN) :: parray_
     INTEGER,     DIMENSION(ijs_:ije_), INTENT(IN) :: jarray_
-    REAL(dp),    DIMENSION(ijgs_:ijge_,ikys:ikye,ikxs:ikxe,izgs:izge,0:1),  INTENT(IN) :: kernel_
+    REAL(dp),    DIMENSION(ijgs_:ijge_,ikys:ikye,ikxs:ikxe,izs:ize,0:1),  INTENT(IN) :: kernel_
     COMPLEX(dp), DIMENSION(ips_:ipe_,ijs_:ije_,ikys:ikye,ikxs:ikxe,izs:ize),INTENT(IN) :: nadiab_moments_
     REAL(dp),    INTENT(IN) :: nu_, sigmaa2_taua_o2, sqrt_sigmaa2_taua_o2
     !! OUTPUT