client.go     |  2 +-
 connection.go | 11 +++++++++--

diff --git a/client.go b/client.go
index 11e855765382edb6196b28d4fbb4e41d2f5f6c91..c12d297b3a72f203403d3b78a9e98fb009bb2b66 100644
--- a/client.go
+++ b/client.go
@@ -325,7 +325,6 @@ 		Socket:          sock,
 		Choked:          true,
 		PeerChoked:      true,
 		write:           make(chan []byte),
-		post:            make(chan pp.Message),
 		PeerMaxRequests: 250, // Default in libtorrent is 250.
 	}
 	defer func() {
@@ -382,6 +381,7 @@ 	defer me.mu.Unlock()
 	if !me.addConnection(torrent, conn) {
 		return
 	}
+	conn.post = make(chan pp.Message)
 	go conn.writeOptimizer(time.Minute)
 	if conn.PeerExtensions[5]&0x10 != 0 {
 		conn.Post(pp.Message{
diff --git a/connection.go b/connection.go
index f507806ad2e36f34ab6f103865ce49006bac9f5c..d7654e7d0ea98e939d03b116935d031cfc2a7490 100644
--- a/connection.go
+++ b/connection.go
@@ -131,13 +131,20 @@ }
 
 func (c *connection) Close() {
 	c.mu.Lock()
+	defer c.mu.Unlock()
 	if c.closed {
 		return
 	}
 	c.Socket.Close()
-	close(c.post)
+	if c.post == nil {
+		// writeOptimizer isn't running, so we need to signal the writer to
+		// stop.
+		close(c.write)
+	} else {
+		// This will kill the writeOptimizer, and it kills the writer.
+		close(c.post)
+	}
 	c.closed = true
-	c.mu.Unlock()
 }
 
 func (c *connection) getClosed() bool {