diff --git a/scrape/helpers_test.go b/scrape/helpers_test.go
index 12a56d7071..7bc9e3f7d4 100644
--- a/scrape/helpers_test.go
+++ b/scrape/helpers_test.go
@@ -46,15 +46,15 @@ type nopAppender struct{}
 func (a nopAppender) SetOptions(opts *storage.AppendOptions) {}
 
 func (a nopAppender) Append(storage.SeriesRef, labels.Labels, int64, float64) (storage.SeriesRef, error) {
-	return 0, nil
+	return 1, nil
 }
 
 func (a nopAppender) AppendExemplar(storage.SeriesRef, labels.Labels, exemplar.Exemplar) (storage.SeriesRef, error) {
-	return 0, nil
+	return 2, nil
 }
 
 func (a nopAppender) AppendHistogram(storage.SeriesRef, labels.Labels, int64, *histogram.Histogram, *histogram.FloatHistogram) (storage.SeriesRef, error) {
-	return 0, nil
+	return 3, nil
 }
 
 func (a nopAppender) AppendHistogramCTZeroSample(ref storage.SeriesRef, l labels.Labels, t, ct int64, h *histogram.Histogram, fh *histogram.FloatHistogram) (storage.SeriesRef, error) {
@@ -62,11 +62,11 @@ func (a nopAppender) AppendHistogramCTZeroSample(ref storage.SeriesRef, l labels
 }
 
 func (a nopAppender) UpdateMetadata(storage.SeriesRef, labels.Labels, metadata.Metadata) (storage.SeriesRef, error) {
-	return 0, nil
+	return 4, nil
 }
 
 func (a nopAppender) AppendCTZeroSample(storage.SeriesRef, labels.Labels, int64, int64) (storage.SeriesRef, error) {
-	return 0, nil
+	return 5, nil
 }
 
 func (a nopAppender) Commit() error   { return nil }