diff --git a/eth/downloader/api.go b/eth/downloader/api.go
index 7a2c028753..6033e44474 100644
--- a/eth/downloader/api.go
+++ b/eth/downloader/api.go
@@ -104,6 +104,9 @@ func (api *DownloaderAPI) eventLoop() {
 			if ev.Type == SyncStarted {
 				started = true
 			}
+		case <-sub.Err():
+			// The downloader is terminated or other internal error occurs
+			return
 		case <-checkTimer.C:
 			if !started {
 				checkTimer.Reset(checkInterval)