diff --git a/components/elm/src/biogeophys/ActiveLayerMod.F90 b/components/elm/src/biogeophys/ActiveLayerMod.F90
index d48f001a1dd1..3ff4d2f098c0 100644
--- a/components/elm/src/biogeophys/ActiveLayerMod.F90
+++ b/components/elm/src/biogeophys/ActiveLayerMod.F90
@@ -190,7 +190,7 @@ subroutine alt_calc(num_soilc, filter_soilc, &
 
          ! update ice wedge polygon microtopographic parameters if in polygonal ground
          ! TODO: need to retrieve landunit this column is on.
-         if (lun_pp%ispolygon) then
+         if (lun_pp%ispolygon(c)) then
             if (lun_pp%polygontype(c) .eq. ilowcenpoly) then
                rmax(c) = 0.4_r8
                vexc(c) = 0.2_r8