1 files changed, 12 insertions, 7 deletions
diff --git a/django/db/models/fields/json.py b/django/db/models/fields/json.py
index 8d743c436a..188fcf520c 100644
--- a/django/db/models/fields/json.py
+++ b/django/db/models/fields/json.py
@@ -99,18 +99,23 @@ class JSONField(CheckFieldDefaultMixin, Field):
     def get_db_prep_value(self, value, connection, prepared=False):
         if not prepared:
             value = self.get_prep_value(value)
-        if isinstance(value, expressions.Value) and isinstance(
-            value.output_field, JSONField
-        ):
-            value = value.value
-        elif hasattr(value, "as_sql"):
-            return value
         return connection.ops.adapt_json_value(value, self.encoder)
 
     def get_db_prep_save(self, value, connection):
+        # This slightly involved logic is to allow for `None` to be used to
+        # store SQL `NULL` while `Value(None, JSONField())` can be used to
+        # store JSON `null` while preventing compilable `as_sql` values from
+        # making their way to `get_db_prep_value`, which is what the `super()`
+        # implementation does.
         if value is None:
             return value
-        return self.get_db_prep_value(value, connection)
+        if (
+            isinstance(value, expressions.Value)
+            and value.value is None
+            and isinstance(value.output_field, JSONField)
+        ):
+            value = None
+        return super().get_db_prep_save(value, connection)
 
     def get_transform(self, name):
         transform = super().get_transform(name)