Breaks in the admin

[jamstooks]

I initially used this in code only and it worked when saving and editing the field. However, the admin widget doesn't seem to work. I get the following when I open the model in the admin and hit save without changing anything:

ValueError: Expecting property name: line 1 column 1 (char 1)

/usr/local/Cellar/python/2.7.1/lib/python2.7/json/decoder.py in raw_decode
line 376: obj, end = self.scan_once(s, idx)