diff --git a/sort.py b/sort.py
index baf665a..aee6dde 100644
--- a/sort.py
+++ b/sort.py
@@ -61,8 +61,8 @@ def convert_bbox_to_z(bbox):
 
 def convert_x_to_bbox(x,score=None):
   """
-  Takes a bounding box in the form [x,y,s,r] and returns it in the form
-    [x1,y1,x2,x2] where x1,y1 is the top left and x2,y2 is the bottom right
+  Takes a bounding box in the centre form [x,y,s,r] and returns it in the form
+    [x1,y1,x2,y2] where x1,y1 is the top left and x2,y2 is the bottom right
   """
   w = np.sqrt(x[2]*x[3])
   h = x[2]/w