diff --git a/cli.py b/cli.py
index 016f294..5dcba2a 100644
--- a/cli.py
+++ b/cli.py
@@ -680,7 +680,9 @@ def dumpjson(self, file, data):
                 boxdata['ybr'] = box.ybr
                 boxdata['outside'] = box.lost
                 boxdata['occluded'] = box.occluded
-                boxdata['attributes'] = box.attributes
+                boxdata['attributes'] = []
+                for attr in box.attributes:
+                    boxdata['attributes'].append(attr.text)
                 boxes[int(box.frame)] = boxdata
             result['boxes'] = boxes
             annotations[int(id)] = result