diff --git a/pkg/store/lazy_postings.go b/pkg/store/lazy_postings.go
index 7e29019e27c..ffcc178d4c3 100644
--- a/pkg/store/lazy_postings.go
+++ b/pkg/store/lazy_postings.go
@@ -38,7 +38,9 @@ func fetchLazyExpandedPostings(
 	var matchers []*labels.Matcher
 	keysToFetch := keys
 	// If all postings added, we always download all postings and then intersect.
-	if lazyExpandedPostingEnabled && !addAllPostings && len(postingGroups) > 1 {
+	// If there is no series max size in meta.json file, skip estimation.
+	if lazyExpandedPostingEnabled && !addAllPostings &&
+		r.block.meta.Thanos.IndexStats.SeriesMaxSize > 0 && len(postingGroups) > 1 {
 		var totalCardinality int64
 		minCardinality := int64(math.MaxInt64)
 		minGroupIdx := -1