diff --git a/nets/ssd_vgg_300.py b/nets/ssd_vgg_300.py
index 117173285..b9af69053 100644
--- a/nets/ssd_vgg_300.py
+++ b/nets/ssd_vgg_300.py
@@ -517,7 +517,6 @@ def ssd_net(inputs,
             localisations.append(l)
 
         return predictions, localisations, logits, end_points
-ssd_net.default_image_size = 300
 
 
 def ssd_arg_scope(weight_decay=0.0005, data_format='NHWC'):