diff --git a/swh/storage/writer.py b/swh/storage/writer.py
index b24de8cd..fb5e4865 100644
--- a/swh/storage/writer.py
+++ b/swh/storage/writer.py
@@ -1,90 +1,88 @@
 # Copyright (C) 2020 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from typing import Iterable
 
 from attr import evolve
 
 from swh.model.model import (
     Origin,
     OriginVisit,
     Snapshot,
     Directory,
     Revision,
     Release,
     Content,
     SkippedContent,
 )
 
 try:
     from swh.journal.writer import get_journal_writer
 except ImportError:
     get_journal_writer = None  # type: ignore
     # mypy limitation, see https://github.com/python/mypy/issues/1153
 
 
 class JournalWriter:
     """Journal writer storage collaborator. It's in charge of adding objects to
     the journal.
 
     """
 
     def __init__(self, journal_writer):
         if journal_writer:
             if get_journal_writer is None:
                 raise EnvironmentError(
                     "You need the swh.journal package to use the "
                     "journal_writer feature"
                 )
             self.journal = get_journal_writer(**journal_writer)
         else:
             self.journal = None
 
     def write_additions(self, obj_type, values):
         if self.journal:
             self.journal.write_additions(obj_type, values)
 
     def content_add(self, contents: Iterable[Content]) -> None:
         """Add contents to the journal. Drop the data field if provided.
 
         """
         contents = [evolve(item, data=None) for item in contents]
         self.write_additions("content", contents)
 
     def content_update(self, contents: Iterable[Content]) -> None:
         if self.journal:
-            raise NotImplementedError(
-                "content_update is not yet supported with a journal writer."
-            )
+            raise NotImplementedError("content_update is not supported by the journal.")
 
     def content_add_metadata(self, contents: Iterable[Content]) -> None:
         self.content_add(contents)
 
     def skipped_content_add(self, contents: Iterable[SkippedContent]) -> None:
         self.write_additions("content", contents)
 
     def directory_add(self, directories: Iterable[Directory]) -> None:
         self.write_additions("directory", directories)
 
     def revision_add(self, revisions: Iterable[Revision]) -> None:
         self.write_additions("revision", revisions)
 
     def release_add(self, releases: Iterable[Release]) -> None:
         self.write_additions("release", releases)
 
     def snapshot_add(self, snapshots: Iterable[Snapshot]) -> None:
         self.write_additions("snapshot", snapshots)
 
     def origin_visit_add(self, visits: Iterable[OriginVisit]):
         self.write_additions("origin_visit", visits)
 
     def origin_visit_update(self, visits: Iterable[OriginVisit]):
         self.write_additions("origin_visit", visits)
 
     def origin_visit_upsert(self, visits: Iterable[OriginVisit]):
         self.write_additions("origin_visit", visits)
 
     def origin_add(self, origins: Iterable[Origin]):
         self.write_additions("origin", origins)