diff --git a/openmc/universe.py b/openmc/universe.py
index 447746e576a..c490ac2989c 100644
--- a/openmc/universe.py
+++ b/openmc/universe.py
@@ -391,7 +391,7 @@ def plot(self, origin=None, width=None, pixels=40000,
 
         bb = self.bounding_box
         # checks to see if bounding box contains -inf or inf values
-        if np.isinf([bb[0][x], bb[1][x], bb[0][y], bb[1][y]]).any():
+        if np.isinf(bb.extent[basis]).any():
             if origin is None:
                 origin = (0, 0, 0)
             if width is None: