diff --git a/internal/locate/region_cache.go b/internal/locate/region_cache.go
index 931f7418..37c61d59 100644
--- a/internal/locate/region_cache.go
+++ b/internal/locate/region_cache.go
@@ -2425,6 +2425,10 @@ func (c *RegionCache) handleRegionInfos(bo *retry.Backoffer, regionsInfo []*rout
 	for _, r := range regionsInfo {
 		// Leader id = 0 indicates no leader.
 		if needLeader && (r.Leader == nil || r.Leader.GetId() == 0) {
+			logutil.BgLogger().Warn("filter out region without leader",
+				zap.Uint64("regionId", r.Meta.Id),
+				zap.String("startKey", redact.Key(r.Meta.StartKey)),
+				zap.String("endKey", redact.Key(r.Meta.EndKey)))
 			continue
 		}
 		region, err := newRegion(bo, c, r)
@@ -2437,7 +2441,7 @@ func (c *RegionCache) handleRegionInfos(bo *retry.Backoffer, regionsInfo []*rout
 		return nil, nil
 	}
 	if len(regions) < len(regionsInfo) {
-		logutil.Logger(context.Background()).Debug(
+		logutil.Logger(context.Background()).Warn(
 			"regionCache: scanRegion finished but some regions has no leader.")
 	}
 	return regions, nil