client.go     |  1 +
 connection.go | 28 ++++++++++++++++++++++++++++

diff --git a/client.go b/client.go
index 3ca57e10a8f3ae12446a871b723d0c13dd6f38cb..e697884e81a192c5c2f5ec0fc358948743abb7e4 100644
--- a/client.go
+++ b/client.go
@@ -401,6 +401,7 @@ 			// TODO: This should be done from a dedicated unchoking routine.
 			conn.Unchoke()
 		case peer_protocol.NotInterested:
 			conn.PeerInterested = false
+			conn.Choke()
 		case peer_protocol.Have:
 			me.peerGotPiece(torrent, conn, int(msg.Index))
 		case peer_protocol.Request:
diff --git a/connection.go b/connection.go
index 136520874c83e11648b2895572aa1db712e841d8..96a1d2154d9676370fe45af843a9f33d82ccaf9b 100644
--- a/connection.go
+++ b/connection.go
@@ -90,6 +90,24 @@ 	return true
 }
 
 // Returns true if an unsatisfied request was canceled.
+func (c *connection) Cancel(r request) bool {
+	if c.Requests == nil {
+		return false
+	}
+	if _, ok := c.Requests[r]; !ok {
+		return false
+	}
+	delete(c.Requests, r)
+	c.Post(peer_protocol.Message{
+		Type:   peer_protocol.Cancel,
+		Index:  r.Index,
+		Begin:  r.Begin,
+		Length: r.Length,
+	})
+	return true
+}
+
+// Returns true if an unsatisfied request was canceled.
 func (c *connection) PeerCancel(r request) bool {
 	if c.PeerRequests == nil {
 		return false
@@ -99,6 +117,16 @@ 		return false
 	}
 	delete(c.PeerRequests, r)
 	return true
+}
+
+func (c *connection) Choke() {
+	if c.Choked {
+		return
+	}
+	c.Post(peer_protocol.Message{
+		Type: peer_protocol.Choke,
+	})
+	c.Choked = true
 }
 
 func (c *connection) Unchoke() {