diff --git a/src/ifcopenshell-python/ifcopenshell/util/shape.py b/src/ifcopenshell-python/ifcopenshell/util/shape.py
index 62cdb0d0f0..77c28ee1ab 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/shape.py
+++ b/src/ifcopenshell-python/ifcopenshell/util/shape.py
@@ -417,7 +417,7 @@ def get_element_top_elevation(element: ifcopenshell.entity_instance, geometry: S
     return max([v[2] for v in get_element_vertices(element, geometry)])
 
 
-def get_bbox(vertices: Iterable[VECTOR_3D]) -> tuple[npt.NDArray[np.float64], npt.NDArray[np.float64]]:
+def get_bbox(vertices: npt.NDArray[np.float64]) -> tuple[npt.NDArray[np.float64], npt.NDArray[np.float64]]:
     """Gets the bounding box of vertices
 
     :param vertices: An iterable of vertices
@@ -426,16 +426,7 @@ def get_bbox(vertices: Iterable[VECTOR_3D]) -> tuple[npt.NDArray[np.float64], np
         right.  E.g.  (np.array([minx, miny, minz]), np.array([maxx, maxy,
         maxz]))
     """
-    x_values = [v[0] for v in vertices]
-    y_values = [v[1] for v in vertices]
-    z_values = [v[2] for v in vertices]
-    minx = min(x_values)
-    maxx = max(x_values)
-    miny = min(y_values)
-    maxy = max(y_values)
-    minz = min(z_values)
-    maxz = max(z_values)
-    return (np.array([minx, miny, minz]), np.array([maxx, maxy, maxz]))
+    return (np.min(vertices, axis=0), np.max(vertices, axis=0))
 
 
 def get_area_vf(vertices: npt.NDArray[np.float64], faces: npt.NDArray[np.int32]) -> float: