diff --git a/quamash/__init__.py b/quamash/__init__.py
index 927fccd..fb883a3 100644
--- a/quamash/__init__.py
+++ b/quamash/__init__.py
@@ -310,6 +310,11 @@ def close(self):
 
 		The loop cannot be restarted after it has been closed.
 		"""
+		if self.is_running():
+			raise RuntimeError("Cannot close a running event loop")
+		if self.is_closed():
+			return
+
 		self._logger.debug('Closing event loop...')
 		if self.__default_executor is not None:
 			self.__default_executor.shutdown()
@@ -376,6 +381,8 @@ def time(self):
 
 	def add_reader(self, fd, callback, *args):
 		"""Register a callback for when a file descriptor is ready for reading."""
+		self._check_closed()
+
 		try:
 			existing = self._read_notifiers[fd]
 		except KeyError:
@@ -397,6 +404,10 @@ def add_reader(self, fd, callback, *args):
 
 	def remove_reader(self, fd):
 		"""Remove reader callback."""
+
+		if self.is_closed():
+			return
+
 		self._logger.debug('Removing reader callback for file descriptor {}'.format(fd))
 		try:
 			notifier = self._read_notifiers.pop(fd)
@@ -408,6 +419,7 @@ def remove_reader(self, fd):
 
 	def add_writer(self, fd, callback, *args):
 		"""Register a callback for when a file descriptor is ready for writing."""
+		self._check_closed()
 		try:
 			existing = self._write_notifiers[fd]
 		except KeyError:
@@ -429,6 +441,10 @@ def add_writer(self, fd, callback, *args):
 
 	def remove_writer(self, fd):
 		"""Remove writer callback."""
+
+		if self.is_closed():
+			return
+
 		self._logger.debug('Removing writer callback for file descriptor {}'.format(fd))
 		try:
 			notifier = self._write_notifiers.pop(fd)
diff --git a/tests/test_qeventloop.py b/tests/test_qeventloop.py
index 84a74a3..3adafc7 100644
--- a/tests/test_qeventloop.py
+++ b/tests/test_qeventloop.py
@@ -399,6 +399,37 @@ def can_read():
 
 	assert got_msg is None, 'Should not have received a read notification'
 
+def test_remove_reader_after_closing(loop, sock_pair):
+	"""Verify that we can remove a reader callback from an event loop."""
+	client_sock, srv_sock = sock_pair
+
+	loop.add_reader(srv_sock.fileno(), lambda: None)
+	loop.close()
+	loop.remove_reader(srv_sock.fileno())
+
+def test_remove_writer_after_closing(loop, sock_pair):
+	"""Verify that we can remove a reader callback from an event loop."""
+	client_sock, srv_sock = sock_pair
+
+	loop.add_writer(client_sock.fileno(), lambda: None)
+	loop.close()
+	loop.remove_writer(client_sock.fileno())
+
+def test_add_reader_after_closing(loop, sock_pair):
+	"""Verify that we can remove a reader callback from an event loop."""
+	client_sock, srv_sock = sock_pair
+
+	loop.close()
+	with pytest.raises(RuntimeError):
+		loop.add_reader(srv_sock.fileno(), lambda:None)
+
+def test_add_writer_after_closing(loop, sock_pair):
+	"""Verify that we can remove a reader callback from an event loop."""
+	client_sock, srv_sock = sock_pair
+
+	loop.close()
+	with pytest.raises(RuntimeError):
+		loop.add_writer(client_sock.fileno(), lambda:None)
 
 def test_can_add_writer(loop, sock_pair):
 	"""Verify that we can add a writer callback to an event loop."""