diff --git a/tests/test27cells.c b/tests/test27cells.c
index c4df8356eb6494cc34b91c6ab5038b3866b14056..7ba1eec9ad279f09f63021e332dac1cfd5cc1505 100644
--- a/tests/test27cells.c
+++ b/tests/test27cells.c
@@ -122,7 +122,7 @@ struct cell *make_cell(size_t n, double *offset, double size, double h,
             break;
         }
         if (h_pert)
-          part->h = size * h * random_uniform(1.f, 1.1f) / (float)n;
+          part->h = size * h * random_uniform(1.f, h_pert) / (float)n;
         else
           part->h = size * h / (float)n;
         h_max = fmaxf(h_max, part->h);