diff --git a/chiral/net/tcp.py b/chiral/net/tcp.py
index a3a62cc..5d1535e 100644
--- a/chiral/net/tcp.py
+++ b/chiral/net/tcp.py
@@ -49,6 +49,7 @@ def connection_handler(self):
 		is initialized. It should be overridden in the derived class.
 		"""
 		raise NotImplementedError
+		yield
 
 	def connection_handler_completed(self, value, exception):
 		"""