diff --git a/platypush/backend/http/__init__.py b/platypush/backend/http/__init__.py
index b2fd7939..9706c063 100644
--- a/platypush/backend/http/__init__.py
+++ b/platypush/backend/http/__init__.py
@@ -239,7 +239,7 @@ class HttpBackend(Backend):
 
             if isinstance(msg, Request):
                 try:
-                    response = msg.execute(async=False)
+                    response = msg.execute(_async=False)
                 except PermissionError:
                     abort(401)
 
diff --git a/platypush/config/__init__.py b/platypush/config/__init__.py
index 96e48ad9..285c55e0 100644
--- a/platypush/config/__init__.py
+++ b/platypush/config/__init__.py
@@ -148,10 +148,10 @@ class Config(object):
                 self.cronjobs[cron_name] = self._config[key]
             elif key.startswith('procedure.'):
                 tokens = key.split('.')
-                async = True if tokens[1] == 'async' else False
+                _async = True if tokens[1] == 'async' else False
                 procedure_name = '.'.join(tokens[2:])
                 self.procedures[procedure_name] = {
-                    'async': async,
+                    'async': _async,
                     'actions': self._config[key]
                 }
             else:
diff --git a/platypush/cron/scheduler.py b/platypush/cron/scheduler.py
index 8b597a7e..2bf46d96 100644
--- a/platypush/cron/scheduler.py
+++ b/platypush/cron/scheduler.py
@@ -27,7 +27,7 @@ class Cronjob(Thread):
         context = {}
 
         for action in self.actions:
-            response = action.execute(async=False, **context)
+            response = action.execute(_async=False, **context)
             logger.info('Response from cronjob {}: {}'.format(self.name, response))
 
 
diff --git a/platypush/message/request/__init__.py b/platypush/message/request/__init__.py
index 3ef9f327..75cc9d09 100644
--- a/platypush/message/request/__init__.py
+++ b/platypush/message/request/__init__.py
@@ -71,7 +71,7 @@ class Request(Message):
         proc_name = self.action.split('.')[-1]
         proc_config = Config.get_procedures()[proc_name]
         proc = Procedure.build(name=proc_name, requests=proc_config['actions'],
-                               async=proc_config['async'],
+                               _async=proc_config['async'],
                                backend=self.backend, id=self.id)
 
         return proc.execute(*args, **kwargs)
diff --git a/platypush/procedure/__init__.py b/platypush/procedure/__init__.py
index ba898cff..56293176 100644
--- a/platypush/procedure/__init__.py
+++ b/platypush/procedure/__init__.py
@@ -11,7 +11,7 @@ logger = logging.getLogger(__name__)
 class Procedure(object):
     """ Procedure class. A procedure is a pre-configured list of requests """
 
-    def __init__(self, name, async, requests, backend=None):
+    def __init__(self, name, _async, requests, backend=None):
         """
         Params:
             name     -- Procedure name
@@ -21,7 +21,7 @@ class Procedure(object):
         """
 
         self.name     = name
-        self.async    = async
+        self._async   = _async
         self.requests = requests
         self.backend  = backend
 
@@ -30,7 +30,7 @@ class Procedure(object):
 
 
     @classmethod
-    def build(cls, name, async, requests, backend=None, id=None, **kwargs):
+    def build(cls, name, _async, requests, backend=None, id=None, **kwargs):
         reqs = []
         loop_count = 0
         if_count = 0
@@ -47,11 +47,11 @@ class Procedure(object):
 
                     # A 'for' loop is synchronous. Declare a 'fork' loop if you
                     # want to process the elements in the iterable in parallel
-                    async = True if m.group(1) == 'fork' else False
+                    _async = True if m.group(1) == 'fork' else False
                     iterator_name = m.group(2)
                     iterable = m.group(3)
 
-                    loop = LoopProcedure.build(name=loop_name, async=async,
+                    loop = LoopProcedure.build(name=loop_name, _async=_async,
                                                requests=request_config[key],
                                                backend=backend, id=id,
                                                iterator_name=iterator_name,
@@ -87,7 +87,7 @@ class Procedure(object):
             request = Request.build(request_config)
             reqs.append(request)
 
-        return cls(name=name, async=async, requests=reqs, backend=backend, **kwargs)
+        return cls(name=name, _async=_async, requests=reqs, backend=backend, **kwargs)
 
 
     def execute(self, n_tries=1, **context):
@@ -105,7 +105,7 @@ class Procedure(object):
             if token:
                 request.token = token
 
-            context['async'] = self.async; context['n_tries'] = n_tries
+            context['async'] = self._async; context['n_tries'] = n_tries
             response = request.execute(**context)
 
             if not self.async:
@@ -145,15 +145,15 @@ class LoopProcedure(Procedure):
 
     context = {}
 
-    def __init__(self, name, iterator_name, iterable, requests, async=False, backend=None, **kwargs):
-        super(). __init__(name=name, async=async, requests=requests, backend=None, **kwargs)
+    def __init__(self, name, iterator_name, iterable, requests, _async=False, backend=None, **kwargs):
+        super(). __init__(name=name, _async=_async, requests=requests, backend=None, **kwargs)
 
         self.iterator_name = iterator_name
         self.iterable = iterable
         self.requests = requests
 
 
-    def execute(self, async=None, **context):
+    def execute(self, _async=None, **context):
         iterable = Request.expand_value_from_context(self.iterable, **context)
         response = Response()