diff --git a/src/whm/whm_getacch.f90 b/src/whm/whm_getacch.f90
index fb21789c0..13eafe05d 100644
--- a/src/whm/whm_getacch.f90
+++ b/src/whm/whm_getacch.f90
@@ -223,6 +223,7 @@ pure subroutine whm_getacch_ah3_tp(cb, pl, tp, xh)
          if (ntp == 0) return
          do i = 1, ntp
             acc(:) = 0.0_DP
+            !$omp simd private(dx,rji2,irij3,fac) reduction(-:acc)
             do j = 1, npl
                dx(:) = xht(:, i) - xh(:, j)
                rji2 = dot_product(dx(:), dx(:))