Why is data returned from django.contrib.postgres.fields.JSONField a string?

Environment:

• Django 1.9.10
• psycopg2 2.6.2
• PostgreSQL 9.5.4 installed via Homebrew on macOS Sierra
• Python 3.5.2 installed via Homebrew

Example model:

from django.db import models
from django.contrib.postgres.fields import JSONField


class Foo(models.Model):
    data = JSONField()

When I try to create an object, everything works as expected:

from myapp.models import Foo
x = Foo()
x.data = {'some key': 'some value'}
x.save()

However, when I try to retrieve that data, the value of the .data attribute is a string:

from myapp.models import Foo
x = Foo.objects.order_by('-id')[0]
# returns "{'some key': 'some value'}"
x.data
# returns <class 'str'>
type(x.data)

My question: how do I get back the dict so I can manipulate data within the JSON field?

EDIT: Using json.loads() fails because the property names and values are enclosed in single quotes rather than double quotes:

import json
json.loads(x.data)
# JSONDecodeError: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)

I can use eval(), but that's obviously extremely dangerous.