diff --git a/benchmarks/stuff.py b/benchmarks/stuff.py
index caf7aeb..4072796 100644
--- a/benchmarks/stuff.py
+++ b/benchmarks/stuff.py
@@ -67,7 +67,7 @@ def fill_timing(arg, f):
     s = mp.Slicer(st, vineyard=(vine == "vine"), dtype=dtype, column_type=col).minpres(
         degree=degree
     )
-    box = mpg.compute_bounding_box(s)
+    box = mpg.compute_bounding_box(s).T
     s.minpres_degree = -1  ## makes it non-minpres again
     if inv == "mma":
         if vine == "vine":
diff --git a/multipers/grids.pyx b/multipers/grids.pyx
index df569e5..79455fc 100644
--- a/multipers/grids.pyx
+++ b/multipers/grids.pyx
@@ -220,7 +220,13 @@ def _todo_partition(some_float[:] data,int resolution, bool unique):
 
 
 def compute_bounding_box(stuff):
-    return np.array(compute_grid(stuff,strategy="regular",resolution=2))
+    r"""
+    Returns a array of shape (2, num_parameters)
+    such that for any filtration value $y$ of something in stuff,
+    then if (x,z) is the output of this function, we have
+    $x\le y \le z$.
+    """
+    return np.array(compute_grid(stuff,strategy="regular",resolution=2)).T
 
 def push_to_grid(some_float[:,:] points, grid, bool return_coordinate=False):
     """