diff --git a/queue_job/jobrunner/channels.py b/queue_job/jobrunner/channels.py
index 3f81ec0b2..54188db11 100644
--- a/queue_job/jobrunner/channels.py
+++ b/queue_job/jobrunner/channels.py
@@ -2,6 +2,7 @@
 # Copyright 2015-2016 Camptocamp SA
 # License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl.html)
 import logging
+from collections import namedtuple
 from functools import total_ordering
 from heapq import heappop, heappush
 from weakref import WeakValueDictionary
@@ -10,6 +11,7 @@
 from ..job import CANCELLED, DONE, ENQUEUED, FAILED, PENDING, STARTED, WAIT_DEPENDENCIES
 
 NOT_DONE = (WAIT_DEPENDENCIES, PENDING, ENQUEUED, STARTED, FAILED)
+JobSortingKey = namedtuple("SortingKey", "eta priority date_created seq")
 
 _logger = logging.getLogger(__name__)
 
@@ -108,7 +110,7 @@ class ChannelJob:
     job that are necessary to prioritise them.
 
     Channel jobs are comparable according to the following rules:
-        * jobs with an eta come before all other jobs
+        * jobs with an eta cannot be compared with jobs without
         * then jobs with a smaller eta come first
         * then jobs with a smaller priority come first
         * then jobs with a smaller creation time come first
@@ -135,14 +137,18 @@ class ChannelJob:
     >>> j3 < j1
     True
 
-    j4 and j5 comes even before j3, because they have an eta
+    j4 and j5 have an eta, they cannot be compared with j3
 
     >>> j4 = ChannelJob(None, None, 4,
     ...                 seq=0, date_created=4, priority=9, eta=9)
     >>> j5 = ChannelJob(None, None, 5,
     ...                 seq=0, date_created=5, priority=9, eta=9)
-    >>> j4 < j5 < j3
+    >>> j4 < j5
     True
+    >>> j4 < j3
+    Traceback (most recent call last):
+     ...
+    TypeError: '<' not supported between instances of 'int' and 'NoneType'
 
     j6 has same date_created and priority as j5 but a smaller eta
 
@@ -153,7 +159,7 @@ class ChannelJob:
 
     Here is the complete suite:
 
-    >>> j6 < j4 < j5 < j3 < j1 < j2
+    >>> j6 < j4 < j5 and j3 < j1 < j2
     True
 
     j0 has the same properties as j1 but they are not considered
@@ -173,14 +179,13 @@ class ChannelJob:
 
     """
 
+    __slots__ = ("db_name", "channel", "uuid", "_sorting_key", "__weakref__")
+
     def __init__(self, db_name, channel, uuid, seq, date_created, priority, eta):
         self.db_name = db_name
         self.channel = channel
         self.uuid = uuid
-        self.seq = seq
-        self.date_created = date_created
-        self.priority = priority
-        self.eta = eta
+        self._sorting_key = JobSortingKey(eta, priority, date_created, seq)
 
     def __repr__(self):
         return "<ChannelJob %s>" % self.uuid
@@ -191,18 +196,36 @@ def __eq__(self, other):
     def __hash__(self):
         return id(self)
 
+    def set_no_eta(self):
+        self._sorting_key = JobSortingKey(None, *self._sorting_key[1:])
+
+    @property
+    def seq(self):
+        return self._sorting_key.seq
+
+    @property
+    def date_created(self):
+        return self._sorting_key.date_created
+
+    @property
+    def priority(self):
+        return self._sorting_key.priority
+
+    @property
+    def eta(self):
+        return self._sorting_key.eta
+
     def sorting_key(self):
-        return self.eta, self.priority, self.date_created, self.seq
+        # DEPRECATED
+        return self._sorting_key
 
     def sorting_key_ignoring_eta(self):
-        return self.priority, self.date_created, self.seq
+        return self._sorting_key[1:]
 
     def __lt__(self, other):
-        if self.eta and not other.eta:
-            return True
-        elif not self.eta and other.eta:
-            return False
-        return self.sorting_key() < other.sorting_key()
+        # Do not compare job where ETA is set with job where it is not
+        # If one job 'eta' is set, and the other is None, it raises TypeError
+        return self._sorting_key < other._sorting_key
 
 
 class ChannelQueue:
@@ -312,7 +335,7 @@ def remove(self, job):
     def pop(self, now):
         while self._eta_queue and self._eta_queue[0].eta <= now:
             eta_job = self._eta_queue.pop()
-            eta_job.eta = None
+            eta_job.set_no_eta()
             self._queue.add(eta_job)
         if self.sequential and self._eta_queue and self._queue:
             eta_job = self._eta_queue[0]