diff --git a/swh/scheduler/task.py b/swh/scheduler/task.py
index 3d16510..b141a01 100644
--- a/swh/scheduler/task.py
+++ b/swh/scheduler/task.py
@@ -1,62 +1,68 @@
 # Copyright (C) 2015-2017 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
 
 import celery.app.task
 from celery.utils.log import get_task_logger
 
 
 class SWHTask(celery.app.task.Task):
     """a schedulable task (abstract class)
 
     Current implementation is based on Celery. See
     http://docs.celeryproject.org/en/latest/reference/celery.app.task.html for
     how to use tasks once instantiated
 
     """
 
     _log = None
 
     def on_failure(self, exc, task_id, args, kwargs, einfo):
         self.send_event('task-result-exception')
 
     def on_success(self, retval, task_id, args, kwargs):
         self.send_event('task-result', result=retval)
 
     @property
     def log(self):
         if self._log is None:
             self._log = get_task_logger(self.name)
         return self._log
 
+    def run(self, *args, **kwargs):
+        self.log.debug('%s: args=%s, kwargs=%s', self.name, args, kwargs)
+        ret = super().run(*args, **kwargs)
+        self.log.debug('%s: OK => %s', self.name, ret)
+        return ret
+
 
 class Task(SWHTask):
     """a schedulable task (abstract class)
 
     DEPRECATED! Please use SWHTask as base for decorated functions instead.
 
     Sub-classes must implement the run_task() method.
 
     Current implementation is based on Celery. See
     http://docs.celeryproject.org/en/latest/reference/celery.app.task.html for
     how to use tasks once instantiated
 
     """
 
     abstract = True
 
     def run(self, *args, **kwargs):
         """This method is called by the celery worker when a task is received.
 
         Should not be overridden as we need our special events to be sent for
         the reccurrent scheduler. Override run_task instead."""
         return self.run_task(*args, **kwargs)
 
     def run_task(self, *args, **kwargs):
         """Perform the task.
 
         Must return a json-serializable value as it is passed back to the task
         scheduler using a celery event.
         """
         raise NotImplementedError('tasks must implement the run_task() method')
diff --git a/swh/scheduler/tests/tasks.py b/swh/scheduler/tests/tasks.py
index 5702680..b18df46 100644
--- a/swh/scheduler/tests/tasks.py
+++ b/swh/scheduler/tests/tasks.py
@@ -1,41 +1,31 @@
-from celery import group
+from celery import group, current_app as app
 
-from swh.scheduler.celery_backend.config import app
 
-
-@app.task(name='swh.scheduler.tests.tasks.ping',
-          bind=True)
+@app.task(name='swh.scheduler.tests.tasks.ping', bind=True)
 def ping(self, **kw):
     # check this is a SWHTask
     assert hasattr(self, 'log')
     assert not hasattr(self, 'run_task')
     assert 'SWHTask' in [x.__name__ for x in self.__class__.__mro__]
     self.log.debug(self.name)
     if kw:
         return 'OK (kw=%s)' % kw
     return 'OK'
 
 
-@app.task(name='swh.scheduler.tests.tasks.multiping',
-          bind=True)
+@app.task(name='swh.scheduler.tests.tasks.multiping', bind=True)
 def multiping(self, n=10):
-    self.log.debug(self.name)
-
     promise = group(ping.s(i=i) for i in range(n))()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, n))
     promise.save()
     return promise.id
 
 
-@app.task(name='swh.scheduler.tests.tasks.error',
-          bind=True)
-def not_implemented(self):
-    self.log.debug(self.name)
+@app.task(name='swh.scheduler.tests.tasks.error')
+def not_implemented():
     raise NotImplementedError('Nope')
 
 
-@app.task(name='swh.scheduler.tests.tasks.add',
-          bind=True)
-def add(self, x, y):
-    self.log.debug(self.name)
+@app.task(name='swh.scheduler.tests.tasks.add')
+def add(x, y):
     return x + y