diff --git a/model/labels/labels_test.go b/model/labels/labels_test.go
index 5a897ac5f..e9eaf7827 100644
--- a/model/labels/labels_test.go
+++ b/model/labels/labels_test.go
@@ -641,6 +641,7 @@ func TestLabels_BytesWithLabels(t *testing.T) {
 
 func TestLabels_BytesWithoutLabels(t *testing.T) {
 	require.Equal(t, Labels{{"aaa", "111"}}.Bytes(nil), Labels{{"aaa", "111"}, {"bbb", "222"}, {"ccc", "333"}}.BytesWithoutLabels(nil, "bbb", "ccc"))
+	require.Equal(t, Labels{{MetricName, "333"}, {"aaa", "111"}}.Bytes(nil), Labels{{MetricName, "333"}, {"aaa", "111"}, {"bbb", "222"}}.BytesWithoutLabels(nil, "bbb"))
 	require.Equal(t, Labels{{"aaa", "111"}}.Bytes(nil), Labels{{MetricName, "333"}, {"aaa", "111"}, {"bbb", "222"}}.BytesWithoutLabels(nil, MetricName, "bbb"))
 }