diff --git a/layers/box_utils.py b/layers/box_utils.py
index 84214947b..d71284c4e 100644
--- a/layers/box_utils.py
+++ b/layers/box_utils.py
@@ -22,8 +22,8 @@ def center_size(boxes):
     Return:
         boxes: (tensor) Converted xmin, ymin, xmax, ymax form of boxes.
     """
-    return torch.cat((boxes[:, 2:] + boxes[:, :2])/2,  # cx, cy
-                     boxes[:, 2:] - boxes[:, :2], 1)  # w, h
+    return torch.cat(((boxes[:, 2:] + boxes[:, :2])/2,  # cx, cy
+                     boxes[:, 2:] - boxes[:, :2]), 1)  # w, h
 
 
 def intersect(box_a, box_b):
diff --git a/layers/functions/prior_box.py b/layers/functions/prior_box.py
index 7848a390d..973030145 100644
--- a/layers/functions/prior_box.py
+++ b/layers/functions/prior_box.py
@@ -2,6 +2,7 @@
 from math import sqrt as sqrt
 from itertools import product as product
 import torch
+from layers.box_utils import point_form, center_size
 
 
 class PriorBox(object):
@@ -51,5 +52,7 @@ def forward(self):
         # back to torch land
         output = torch.Tensor(mean).view(-1, 4)
         if self.clip:
+            output = point_form(output)
             output.clamp_(max=1, min=0)
+            output = center_size(output)
         return output