diff --git a/prompb/io/prometheus/write/v2/custom_test.go b/prompb/io/prometheus/write/v2/custom_test.go
index 139cbfb225..d565461ec8 100644
--- a/prompb/io/prometheus/write/v2/custom_test.go
+++ b/prompb/io/prometheus/write/v2/custom_test.go
@@ -30,7 +30,7 @@ func TestOptimizedMarshal(t *testing.T) {
 		{
 			name: "simple",
 			m: &Request{
-				Timeseries: []TimeSeries{
+				Timeseries: []*TimeSeries{
 					{
 						LabelsRefs: []uint32{
 							0, 1,
@@ -43,14 +43,14 @@ func TestOptimizedMarshal(t *testing.T) {
 							14, 15,
 						},
 
-						Samples:    []Sample{{Value: 1, Timestamp: 0}},
-						Exemplars:  []Exemplar{{LabelsRefs: []uint32{0, 1}, Value: 1, Timestamp: 0}},
+						Samples:    []*Sample{{Value: 1, Timestamp: 0}},
+						Exemplars:  []*Exemplar{{LabelsRefs: []uint32{0, 1}, Value: 1, Timestamp: 0}},
 						Histograms: nil,
 					},
 					{
 						LabelsRefs: []uint32{
 							0, 1,
-							2, 3,
+							2, 3,	
 							4, 5,
 							6, 7,
 							8, 9,
@@ -58,8 +58,8 @@ func TestOptimizedMarshal(t *testing.T) {
 							12, 13,
 							14, 15,
 						},
-						Samples:    []Sample{{Value: 2, Timestamp: 1}},
-						Exemplars:  []Exemplar{{LabelsRefs: []uint32{0, 1}, Value: 2, Timestamp: 1}},
+						Samples:    []*Sample{{Value: 2, Timestamp: 1}},
+						Exemplars:  []*Exemplar{{LabelsRefs: []uint32{0, 1}, Value: 2, Timestamp: 1}},
 						Histograms: nil,
 					},
 				},
@@ -82,7 +82,7 @@ func TestOptimizedMarshal(t *testing.T) {
 			got := make([]byte, 0)
 
 			// Should be the same as the standard marshal.
-			expected, err := tt.m.Marshal()
+			expected, err := tt.m.MarshalVT()
 			require.NoError(t, err)
 			got, err = tt.m.OptimizedMarshal(got)
 			require.NoError(t, err)
@@ -90,7 +90,7 @@ func TestOptimizedMarshal(t *testing.T) {
 
 			// Unmarshal should work too.
 			m := &Request{}
-			require.NoError(t, m.Unmarshal(got))
+			require.NoError(t, m.UnmarshalVT(got))
 			require.Equal(t, tt.m, m)
 		})
 	}
diff --git a/prompb/rwcommon/codec_test.go b/prompb/rwcommon/codec_test.go
index bafc9bdeec..c76c5c1b4f 100644
--- a/prompb/rwcommon/codec_test.go
+++ b/prompb/rwcommon/codec_test.go
@@ -128,7 +128,7 @@ func TestToMetadata(t *testing.T) {
 	} {
 		t.Run("", func(t *testing.T) {
 			ts := writev2.TimeSeries{Metadata: tc.input}
-			require.Equal(t, tc.expected, ts.ToMetadata(sym.Symbols()))
+			require.Equal(t, *tc.expected, ts.ToMetadata(sym.Symbols()))
 		})
 	}
 }
@@ -139,8 +139,8 @@ func TestToHistogram_Empty(t *testing.T) {
 		require.NotNilf(t, prompb.Histogram{}.ToFloatHistogram(), "")
 	})
 	t.Run("v2", func(t *testing.T) {
-		require.NotNilf(t, writev2.Histogram{}.ToIntHistogram(), "")
-		require.NotNilf(t, writev2.Histogram{}.ToFloatHistogram(), "")
+		require.NotNilf(t, (&writev2.Histogram{}).ToIntHistogram(), "")
+		require.NotNilf(t, (&writev2.Histogram{}).ToFloatHistogram(), "")
 	})
 }