diff --git a/tsdb/index/postings.go b/tsdb/index/postings.go
index 603e645f9..b4e98a872 100644
--- a/tsdb/index/postings.go
+++ b/tsdb/index/postings.go
@@ -403,7 +403,7 @@ func (p *MemPostings) PostingsForLabelMatching(ctx context.Context, name string,
 			return ErrPostings(ctx.Err())
 		}
 
-		if match == nil || match(vals[i]) {
+		if match(vals[i]) {
 			i++
 			continue
 		}