client.go | 10 +++++++++-

diff --git a/client.go b/client.go
index f7b5ebaeee560bf2ca858e12ac93a722357754a8..629b708b7f6bc3544c6b6cfb9b450f793b8fb335 100644
--- a/client.go
+++ b/client.go
@@ -539,6 +539,7 @@ 	}
 }
 
 func (me *Client) Stop() {
+	me.Lock()
 	close(me.quit)
 	me.event.Broadcast()
 	for _, t := range me.torrents {
@@ -546,6 +547,7 @@ 		for _, c := range t.Conns {
 			c.Close()
 		}
 	}
+	me.Unlock()
 }
 
 func (cl *Client) acceptConnections() {
@@ -679,7 +681,13 @@ 		PeerChoked: true,
 		write:      make(chan []byte),
 		post:       make(chan encoding.BinaryMarshaler),
 	}
-	defer conn.Close()
+	defer func() {
+		// There's a lock and deferred unlock later in this function. The
+		// client will not be locked when this deferred is invoked.
+		me.mu.Lock()
+		defer me.mu.Unlock()
+		conn.Close()
+	}()
 	go conn.writer()
 	go conn.writeOptimizer()
 	conn.post <- peer_protocol.Bytes(peer_protocol.Protocol)