diff --git a/storage/completion.go b/storage/completion.go
index 13c99e2d..a5c28fcb 100644
--- a/storage/completion.go
+++ b/storage/completion.go
@@ -7,8 +7,8 @@ import (
 )
 
 type pieceCompletion interface {
-	Get(metainfo.Piece) bool
-	Set(metainfo.Piece, bool)
+	Get(metainfo.Piece) (bool, error)
+	Set(metainfo.Piece, bool) error
 	Close()
 }
 
diff --git a/storage/completion_piece_map.go b/storage/completion_piece_map.go
index 8b904fb9..b8a2d5b4 100644
--- a/storage/completion_piece_map.go
+++ b/storage/completion_piece_map.go
@@ -10,12 +10,12 @@ type mapPieceCompletion struct {
 
 func (mapPieceCompletion) Close() {}
 
-func (me *mapPieceCompletion) Get(p metainfo.Piece) bool {
+func (me *mapPieceCompletion) Get(p metainfo.Piece) (bool, error) {
 	_, ok := me.m[p.Key()]
-	return ok
+	return ok, nil
 }
 
-func (me *mapPieceCompletion) Set(p metainfo.Piece, b bool) {
+func (me *mapPieceCompletion) Set(p metainfo.Piece, b bool) error {
 	if b {
 		if me.m == nil {
 			me.m = make(map[metainfo.PieceKey]struct{})
@@ -24,4 +24,5 @@ func (me *mapPieceCompletion) Set(p metainfo.Piece, b bool) {
 	} else {
 		delete(me.m, p.Key())
 	}
+	return nil
 }
diff --git a/storage/db.go b/storage/db.go
index f7e126d0..db95a11d 100644
--- a/storage/db.go
+++ b/storage/db.go
@@ -26,25 +26,19 @@ func newDBPieceCompletion(dir string) (ret *dbPieceCompletion, err error) {
 	return
 }
 
-func (me *dbPieceCompletion) Get(p metainfo.Piece) (ret bool) {
+func (me *dbPieceCompletion) Get(p metainfo.Piece) (ret bool, err error) {
 	row := me.db.QueryRow(`select exists(select * from completed where infohash=? and "index"=?)`, p.Info.Hash().HexString(), p.Index())
-	err := row.Scan(&ret)
-	if err != nil {
-		panic(err)
-	}
+	err = row.Scan(&ret)
 	return
 }
 
-func (me *dbPieceCompletion) Set(p metainfo.Piece, b bool) {
-	var err error
+func (me *dbPieceCompletion) Set(p metainfo.Piece, b bool) (err error) {
 	if b {
 		_, err = me.db.Exec(`insert into completed (infohash, "index") values (?, ?)`, p.Info.Hash().HexString(), p.Index())
 	} else {
 		_, err = me.db.Exec(`delete from completed where infohash=? and "index"=?`, p.Info.Hash().HexString(), p.Index())
 	}
-	if err != nil {
-		panic(err)
-	}
+	return
 }
 
 func (me *dbPieceCompletion) Close() {
diff --git a/storage/file_storage_piece.go b/storage/file_storage_piece.go
index fec993a3..44648c13 100644
--- a/storage/file_storage_piece.go
+++ b/storage/file_storage_piece.go
@@ -14,10 +14,10 @@ type fileStoragePiece struct {
 	r io.ReaderAt
 }
 
-func (fs *fileStoragePiece) GetIsComplete() (ret bool) {
-	ret = fs.completion.Get(fs.p)
-	if !ret {
-		return
+func (fs *fileStoragePiece) GetIsComplete() bool {
+	ret, err := fs.completion.Get(fs.p)
+	if err != nil || !ret {
+		return false
 	}
 	// If it's allegedly complete, check that its constituent files have the
 	// necessary length.
@@ -29,11 +29,11 @@ func (fs *fileStoragePiece) GetIsComplete() (ret bool) {
 		}
 	}
 	if ret {
-		return
+		return true
 	}
 	// The completion was wrong, fix it.
 	fs.completion.Set(fs.p, false)
-	return
+	return false
 }
 
 func (fs *fileStoragePiece) MarkComplete() error {
diff --git a/storage/mmap.go b/storage/mmap.go
index 836b6f0f..6a81f26e 100644
--- a/storage/mmap.go
+++ b/storage/mmap.go
@@ -58,8 +58,9 @@ type mmapStoragePiece struct {
 	io.WriterAt
 }
 
-func (sp mmapStoragePiece) GetIsComplete() bool {
-	return sp.pc.Get(sp.p)
+func (sp mmapStoragePiece) GetIsComplete() (ret bool) {
+	ret, _ = sp.pc.Get(sp.p)
+	return
 }
 
 func (sp mmapStoragePiece) MarkComplete() error {