diff --git a/ddl/ingest/engine.go b/ddl/ingest/engine.go
index ac0287b26637a..fce350df09e40 100644
--- a/ddl/ingest/engine.go
+++ b/ddl/ingest/engine.go
@@ -204,7 +204,7 @@ func (ei *engineInfo) newWriterContext(workerID int, unique bool) (*WriterContex
 
 func (ei *engineInfo) closeWriters() error {
 	var firstErr error
-	for wid := range ei.writerCache.Keys() {
+	for _, wid := range ei.writerCache.Keys() {
 		if w, ok := ei.writerCache.Load(wid); ok {
 			_, err := w.Close(ei.ctx)
 			if err != nil {