reader.go  | 4 ++--
 torrent.go | 7 +++++++

diff --git a/reader.go b/reader.go
index 0f92343a20c3b448d8567b8e37a2071836f030a7..f0b81668d4279c69a74fe43dfeec527b16637954 100644
--- a/reader.go
+++ b/reader.go
@@ -136,8 +136,8 @@ 			return
 		}
 		log.Printf("%s: error reading from torrent storage pos=%d: %s", r.t, pos, err)
 		r.t.cl.mu.Lock()
-		r.t.torrent.updatePieceCompletion(pi)
-		r.t.torrent.updatePiecePriority(pi)
+		r.t.torrent.updateAllPieceCompletions()
+		r.t.torrent.updatePiecePriorities()
 		r.t.cl.mu.Unlock()
 	}
 }
diff --git a/torrent.go b/torrent.go
index daca65c0a3871fe2fc4a3e1146150a2c6e8a86dc..3bbbcef8623bb73417fdc83b0dde7ad650403a8f 100644
--- a/torrent.go
+++ b/torrent.go
@@ -17,6 +17,7 @@ 	"github.com/anacrolix/missinggo/bitmap"
 	"github.com/anacrolix/missinggo/itertools"
 	"github.com/anacrolix/missinggo/perf"
 	"github.com/anacrolix/missinggo/pubsub"
+	"github.com/bradfitz/iter"
 
 	"github.com/anacrolix/torrent/bencode"
 	"github.com/anacrolix/torrent/metainfo"
@@ -1050,3 +1051,9 @@ 		t.Pieces[pi].waitNoPendingWrites()
 	}
 	return t.data.ReadAt(b, off)
 }
+
+func (t *torrent) updateAllPieceCompletions() {
+	for i := range iter.N(t.numPieces()) {
+		t.updatePieceCompletion(i)
+	}
+}