diff --git a/ox/django/fields.py b/ox/django/fields.py
index 2ff69d8..83e11f0 100644
--- a/ox/django/fields.py
+++ b/ox/django/fields.py
@@ -49,57 +49,49 @@ class DictField(models.TextField):
 
     # Used so to_python() is called
     __metaclass__ = models.SubfieldBase
+    _type = dict
+
+    def loads(self, value):
+        return json.loads(value, object_hook=from_json)
+
+    def dumps(self, obj):
+        return json.dumps(obj, default=to_json)
 
     def to_python(self, value):
-        """Convert our string value to python after we load it from the DB"""
-        if value == None:
+        # django 1.7
+        if value is None:
             return value
-        if isinstance(value, dict):
+        if isinstance(value, self._type):
             return value
         try:
-            value = json.loads(value, object_hook=from_json)
-        except: #this is required to load fixtures
-            value = eval(value)
-        assert isinstance(value, dict)
+            value = self.loads(value)
+        except:
+            raise Exception('failed to parse value: %s' % value)
+        if value is not None:
+            assert isinstance(value, self._type)
         return value
 
-    def get_db_prep_save(self, value, connection):
-        """Convert our JSON object to a string before we save"""
-        if value == None:
-            return value
-        if isinstance(value, string_types):
-            value = eval(value)
-        assert isinstance(value, dict)
-        value = json.dumps(value, default=to_json)
-        return super(DictField, self).get_db_prep_save(value, connection=connection)
+    def from_db_value(self, value, expression, connection, context):
+        # django 1.8
+        return self.to_python(value)
 
-class TupleField(models.TextField):
-    """TupleField is a textfield that contains JSON-serialized tuples."""
+    def get_prep_value(self, value):
+        if isinstance(value, self._type):
+            value = self.dumps(value)
+        if value is not None:
+            assert isinstance(value, string_types)
+        value = models.TextField.get_prep_value(self, value)
+        return value
 
-    # Used so to_python() is called
-    __metaclass__ = models.SubfieldBase
 
-    def to_python(self, value):
-        """Convert our string value to JSON after we load it from the DB"""
-        if isinstance(value, tuple):
-            return value
+class TupleField(DictField):
+    _type = tuple
 
-        try:
-            value = json.loads(value, object_hook=from_json)
-        except: #this is required to load fixtures
-            value = eval(value)
-        assert isinstance(value, list)
-        return tuple(value)
-
-    def get_db_prep_save(self, value, connection):
-        """Convert our JSON object to a string before we save"""
-        if isinstance(value, string_types):
-            value = eval(value)
-            if isinstance(value, list):
-                value = tuple(value)
-        assert isinstance(value, tuple)
-        value = json.dumps(value, default=to_json)
-        return super(TupleField, self).get_db_prep_save(value, connection=connection)
+    def loads(self, value):
+        value = DictField.loads(self, value)
+        if isinstance(value, list):
+            value = tuple(value)
+        return value
 
 try:
     from south.modelsinspector import add_introspection_rules