diff --git a/waflib/Runner.py b/waflib/Runner.py
index 01c3df1e..4ad1975b 100644
--- a/waflib/Runner.py
+++ b/waflib/Runner.py
@@ -29,12 +29,13 @@ class Consumer(Utils.threading.Thread):
 		self.start()
 	def run(self):
 		try:
-			self.task.process()
+			if not self.spawner.master.stop:
+				self.task.process()
 		finally:
+			self.spawner.sem.release()
 			self.spawner.master.out.put(self.task)
-		self.spawner.sem.release()
-		self.task = None
-		self.spawner = None
+			self.task = None
+			self.spawner = None
 
 class Spawner(Utils.threading.Thread):
 	def __init__(self, master):
diff --git a/waflib/Task.py b/waflib/Task.py
index 8eb67772..ff79e5b7 100644
--- a/waflib/Task.py
+++ b/waflib/Task.py
@@ -200,14 +200,10 @@ class TaskBase(evil):
 		Assume that the task has had a ``master`` which is an instance of :py:class:`waflib.Runner.Parallel`.
 		Execute the task and then put it back in the queue :py:attr:`waflib.Runner.Parallel.out` (may be replaced by subclassing).
 		"""
-		m = self.generator.bld.producer
-		if m.stop:
-			return
-
 		# remove the task signature immediately before it is executed
 		# in case of failure the task will be executed again
 		try:
-			# TODO waf 1.9 - this breaks encapsulation
+			# TODO another place for this?
 			del self.generator.bld.task_sigs[self.uid()]
 		except KeyError:
 			pass