diff --git a/mypy.ini b/mypy.ini
--- a/mypy.ini
+++ b/mypy.ini
@@ -19,3 +19,6 @@
 
 [mypy-pytest_kafka.*]
 ignore_missing_imports = True
+
+[mypy-systemd.daemon.*]
+ignore_missing_imports = True
diff --git a/swh/journal/cli.py b/swh/journal/cli.py
--- a/swh/journal/cli.py
+++ b/swh/journal/cli.py
@@ -11,6 +11,11 @@
 
 import click
 
+try:
+    from systemd.daemon import notify
+except ImportError:
+    notify = None
+
 from swh.core import config
 from swh.core.cli import CONTEXT_SETTINGS
 from swh.model.model import SHA1_SIZE
@@ -93,11 +98,16 @@
         max_messages=max_messages)
     worker_fn = functools.partial(process_replay_objects, storage=storage)
 
+    if notify:
+        notify('READY=1')
+
     try:
         nb_messages = 0
         last_log_time = 0
         while not max_messages or nb_messages < max_messages:
             nb_messages += client.process(worker_fn)
+            if notify:
+                notify('WATCHDOG=1')
             if time.time() - last_log_time >= 60:
                 # Log at most once per minute.
                 logger.info('Processed %d messages.' % nb_messages)
@@ -107,6 +117,8 @@
     else:
         print('Done.')
     finally:
+        if notify:
+            notify('STOPPING=1')
         client.close()
 
 
@@ -135,12 +147,18 @@
     """
     conf = ctx.obj['config']
     backfiller = JournalBackfiller(conf)
+
+    if notify:
+        notify('READY=1')
+
     try:
         backfiller.run(
             object_type=object_type,
             start_object=start_object, end_object=end_object,
             dry_run=dry_run)
     except KeyboardInterrupt:
+        if notify:
+            notify('STOPPING=1')
         ctx.exit(0)
 
 
@@ -212,11 +230,16 @@
                                   dst=objstorage_dst,
                                   exclude_fn=exclude_fn)
 
+    if notify:
+        notify('READY=1')
+
     try:
         nb_messages = 0
         last_log_time = 0
         while not max_messages or nb_messages < max_messages:
             nb_messages += client.process(worker_fn)
+            if notify:
+                notify('WATCHDOG=1')
             if time.time() - last_log_time >= 60:
                 # Log at most once per minute.
                 logger.info('Processed %d messages.' % nb_messages)
@@ -225,6 +248,10 @@
         ctx.exit(0)
     else:
         print('Done.')
+    finally:
+        if notify:
+            notify('STOPPING=1')
+        client.close()
 
 
 def main():
diff --git a/swh/journal/replay.py b/swh/journal/replay.py
--- a/swh/journal/replay.py
+++ b/swh/journal/replay.py
@@ -8,6 +8,11 @@
 import logging
 from contextlib import contextmanager
 
+try:
+    from systemd.daemon import notify
+except ImportError:
+    notify = None
+
 from swh.core.statsd import statsd
 from swh.model.identifiers import normalize_timestamp
 from swh.model.hashutil import hash_to_hex
@@ -32,6 +37,8 @@
             _insert_objects(object_type, objects, storage)
         statsd.increment(GRAPH_OPERATIONS_METRIC, len(objects),
                          tags={'object_type': object_type})
+    if notify:
+        notify('WATCHDOG=1')
 
 
 def _fix_revision_pypi_empty_string(rev):
@@ -404,3 +411,6 @@
         sum(vol)/1024/1024/dt,
         len([x for x in vol if not x]),
         nb_skipped)
+
+    if notify:
+        notify('WATCHDOG=1')