diff --git a/internal/telemetry/export/ocagent/wire/metrics.go b/internal/telemetry/export/ocagent/wire/metrics.go
index ea82becfd2..d9ff519f10 100644
--- a/internal/telemetry/export/ocagent/wire/metrics.go
+++ b/internal/telemetry/export/ocagent/wire/metrics.go
@@ -4,6 +4,11 @@
 
 package wire
 
+import (
+	"encoding/json"
+	"fmt"
+)
+
 type ExportMetricsServiceRequest struct {
 	Node     *Node     `json:"node,omitempty"`
 	Metrics  []*Metric `json:"metrics,omitempty"`
@@ -62,6 +67,48 @@ type PointInt64Value struct {
 	Int64Value int64 `json:"int64Value,omitempty"`
 }
 
+// MarshalJSON creates JSON formatted the same way as jsonpb so that the
+// OpenCensus service can correctly determine the underlying value type.
+// This custom MarshalJSON exists because,
+// by default *Point is JSON marshalled as:
+//     {"value": {"int64Value": 1}}
+// but it should be marshalled as:
+//     {"int64Value": 1}
+func (p *Point) MarshalJSON() ([]byte, error) {
+	if p == nil {
+		return []byte("null"), nil
+	}
+
+	switch d := p.Value.(type) {
+	case PointInt64Value:
+		return json.Marshal(&struct {
+			Timestamp *Timestamp `json:"timestamp,omitempty"`
+			Value     int64      `json:"int64Value,omitempty"`
+		}{
+			Timestamp: p.Timestamp,
+			Value:     d.Int64Value,
+		})
+	case PointDoubleValue:
+		return json.Marshal(&struct {
+			Timestamp *Timestamp `json:"timestamp,omitempty"`
+			Value     float64    `json:"doubleValue,omitempty"`
+		}{
+			Timestamp: p.Timestamp,
+			Value:     d.DoubleValue,
+		})
+	case PointDistributionValue:
+		return json.Marshal(&struct {
+			Timestamp *Timestamp         `json:"timestamp,omitempty"`
+			Value     *DistributionValue `json:"distributionValue,omitempty"`
+		}{
+			Timestamp: p.Timestamp,
+			Value:     d.DistributionValue,
+		})
+	default:
+		return nil, fmt.Errorf("unknown point type %T", p.Value)
+	}
+}
+
 type PointDoubleValue struct {
 	DoubleValue float64 `json:"doubleValue,omitempty"`
 }
diff --git a/internal/telemetry/export/ocagent/wire/metrics_test.go b/internal/telemetry/export/ocagent/wire/metrics_test.go
new file mode 100644
index 0000000000..b510ee29cc
--- /dev/null
+++ b/internal/telemetry/export/ocagent/wire/metrics_test.go
@@ -0,0 +1,76 @@
+package wire
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestMarshalJSON(t *testing.T) {
+	tests := []struct {
+		name string
+		pt   *Point
+		want string
+	}{
+		{
+			"PointInt64",
+			&Point{
+				Value: PointInt64Value{
+					Int64Value: 5,
+				},
+			},
+			`{"int64Value":5}`,
+		},
+		{
+			"PointDouble",
+			&Point{
+				Value: PointDoubleValue{
+					DoubleValue: 3.14,
+				},
+			},
+			`{"doubleValue":3.14}`,
+		},
+		{
+			"PointDistribution",
+			&Point{
+				Value: PointDistributionValue{
+					DistributionValue: &DistributionValue{
+						Count: 3,
+						Sum:   10,
+						Buckets: []*Bucket{
+							{
+								Count: 1,
+							},
+							{
+								Count: 2,
+							},
+						},
+						BucketOptions: BucketOptionsExplicit{
+							Bounds: []float64{
+								0, 5,
+							},
+						},
+					},
+				},
+			},
+			`{"distributionValue":{"count":3,"sum":10,"bucket_options":{"bounds":[0,5]},"buckets":[{"count":1},{"count":2}]}}`,
+		},
+		{
+			"nil point",
+			nil,
+			`null`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf, err := tt.pt.MarshalJSON()
+			if err != nil {
+				t.Fatalf("Got:\n%v\nWant:\n%v", err, nil)
+			}
+			got := string(buf)
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Fatalf("Got:\n%s\nWant:\n%s", got, tt.want)
+			}
+		})
+	}
+}