diff --git a/src/common/m_finite_differences.fpp b/src/common/m_finite_differences.fpp
index 09dba0a903..e44b6905c0 100644
--- a/src/common/m_finite_differences.fpp
+++ b/src/common/m_finite_differences.fpp
@@ -50,7 +50,7 @@ contains
                         if (z == iz_s%beg) then
                             divergence = divergence + (-3._wp*fields(3)%sf(x, y, z) + 4._wp*fields(3)%sf(x, y, z + 1) - fields(3)%sf(x, y, z + 2))/(z_cc(z + 2) - z_cc(z))
                         else if (z == iz_s%end) then
-                            divergence = divergence + (+3._wp*fields(3)%sf(x, y, z) - 4._wp*fields(3)%sf(x, y, z - 1) + fields(2)%sf(x, y, z - 2))/(z_cc(z) - z_cc(z - 2))
+                            divergence = divergence + (+3._wp*fields(3)%sf(x, y, z) - 4._wp*fields(3)%sf(x, y, z - 1) + fields(3)%sf(x, y, z - 2))/(z_cc(z) - z_cc(z - 2))
                         else
                             divergence = divergence + (fields(3)%sf(x, y, z + 1) - fields(3)%sf(x, y, z - 1))/(z_cc(z + 1) - z_cc(z - 1))
                         end if