peerconn.go | 3 ++-
 piece.go    | 1 +

diff --git a/peerconn.go b/peerconn.go
index d975af4f42675c4396922ce0a7d195b73357f6f1..48acbc111f111386b06c76254af616043c430f54 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -1354,7 +1354,8 @@ 	}
 
 	c.onDirtiedPiece(pieceIndex(req.Index))
 
-	if t.pieceAllDirty(pieceIndex(req.Index)) {
+	// We need to ensure the piece is only queued once, so only the last chunk writer gets this job.
+	if t.pieceAllDirty(pieceIndex(req.Index)) && piece.pendingWrites == 0 {
 		t.queuePieceCheck(pieceIndex(req.Index))
 		// We don't pend all chunks here anymore because we don't want code dependent on the dirty
 		// chunk status (such as the haveChunk call above) to have to check all the various other
diff --git a/piece.go b/piece.go
index 2e6a4259a109b7579ad37370c71bccebf6e7d6cc..56dedec6d044c954fcf7364908e8bef9dfc1a8bb 100644
--- a/piece.go
+++ b/piece.go
@@ -55,6 +55,7 @@
 	publicPieceState PieceState
 	priority         piecePriority
 
+	// This can be locked when the Client lock is taken, but probably not vice versa.
 	pendingWritesMutex sync.Mutex
 	pendingWrites      int
 	noPendingWrites    sync.Cond