diff --git a/tsdb/head.go b/tsdb/head.go
index b0124922e..5f0ae3c6b 100644
--- a/tsdb/head.go
+++ b/tsdb/head.go
@@ -602,6 +602,7 @@ func (h *Head) loadWAL(r *wal.Reader, multiRef map[uint64]uint64, mmappedChunks
 	wg.Add(1)
 	exemplarsInput = make(chan record.RefExemplar, 300)
 	go func(input <-chan record.RefExemplar) {
+		var err error
 		defer wg.Done()
 		for e := range input {
 			ms := h.series.getByID(e.Ref)