diff --git a/tests/test27cells.c b/tests/test27cells.c
index a0f541d17100a13079580aabbef065fa5adbd5e1..2377cef7b36ca347e8e8729b9f1f3a690d92d164 100644
--- a/tests/test27cells.c
+++ b/tests/test27cells.c
@@ -156,7 +156,7 @@ struct cell *make_cell(size_t n, double *offset, double size, double h,
 
   /* Cell properties */
   cell->split = 0;
-  cell->h_max = h;
+  cell->h_max = size * h / (float)n;
   cell->count = count;
   cell->dx_max_part = 0.;
   cell->dx_max_sort = 0.;