diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 58d19254c..b8eaa6a5e 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -719,7 +719,7 @@ func (d *Downloader) findAncestor(p *peerConnection, remoteHeader *types.Header)
 			}
 			// Make sure the peer's reply conforms to the request
 			for i, header := range headers {
-				expectNumber := from + int64(i)*int64((skip+1))
+				expectNumber := from + int64(i)*int64(skip+1)
 				if number := header.Number.Int64(); number != expectNumber {
 					p.log.Warn("Head headers broke chain ordering", "index", i, "requested", expectNumber, "received", number)
 					return 0, errInvalidChain