diff --git a/prompb/io/prometheus/client/metrics.pb.go b/prompb/io/prometheus/client/metrics.pb.go
index e6623e9e1..702ee62fc 100644
--- a/prompb/io/prometheus/client/metrics.pb.go
+++ b/prompb/io/prometheus/client/metrics.pb.go
@@ -878,6 +878,7 @@ type MetricFamily struct {
 	Help                 string     `protobuf:"bytes,2,opt,name=help,proto3" json:"help,omitempty"`
 	Type                 MetricType `protobuf:"varint,3,opt,name=type,proto3,enum=io.prometheus.client.MetricType" json:"type,omitempty"`
 	Metric               []Metric   `protobuf:"bytes,4,rep,name=metric,proto3" json:"metric"`
+	Unit                 string     `protobuf:"bytes,5,opt,name=unit,proto3" json:"unit,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}   `json:"-"`
 	XXX_unrecognized     []byte     `json:"-"`
 	XXX_sizecache        int32      `json:"-"`
@@ -944,6 +945,13 @@ func (m *MetricFamily) GetMetric() []Metric {
 	return nil
 }
 
+func (m *MetricFamily) GetUnit() string {
+	if m != nil {
+		return m.Unit
+	}
+	return ""
+}
+
 func init() {
 	proto.RegisterEnum("io.prometheus.client.MetricType", MetricType_name, MetricType_value)
 	proto.RegisterType((*LabelPair)(nil), "io.prometheus.client.LabelPair")
@@ -965,67 +973,68 @@ func init() {
 }
 
 var fileDescriptor_d1e5ddb18987a258 = []byte{
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+	0x70, 0xce, 0x16, 0x81, 0xa9, 0x1a, 0x07, 0xba, 0xeb, 0x6e, 0x09, 0xd4, 0x33, 0x03, 0xe7, 0x6c,
+	0x11, 0x98, 0xa9, 0x7e, 0x2b, 0x9b, 0xc9, 0xd6, 0x40, 0xdd, 0x94, 0x71, 0xce, 0x46, 0x9f, 0x83,
+	0xb9, 0xce, 0xdb, 0xb0, 0x6c, 0x22, 0x5b, 0xed, 0x29, 0xba, 0x35, 0x2e, 0x23, 0x44, 0xe3, 0x2e,
+	0x1c, 0x77, 0xc3, 0x54, 0x76, 0xaa, 0x1a, 0xee, 0x14, 0xd8, 0x24, 0x75, 0x7e, 0x31, 0x60, 0x47,
+	0xdd, 0xc3, 0x23, 0x12, 0xfa, 0xc1, 0x45, 0xe5, 0x27, 0x02, 0x82, 0xfa, 0x9a, 0x06, 0xb1, 0xfe,
+	0x42, 0x90, 0x6b, 0x74, 0x17, 0xea, 0x42, 0xa3, 0xb4, 0x70, 0x77, 0xdb, 0x7f, 0x5e, 0x65, 0x9e,
+	0x5d, 0xc4, 0x14, 0x4b, 0xb6, 0x68, 0xed, 0xea, 0x5b, 0xc7, 0xae, 0x5f, 0xd7, 0xda, 0x55, 0x5c,
+	0xde, 0xda, 0x55, 0x84, 0x50, 0x91, 0x45, 0x3e, 0x97, 0x16, 0x9a, 0x58, 0xae, 0xdf, 0x5b, 0x00,
+	0x94, 0x67, 0xa0, 0x0e, 0xb4, 0x1e, 0x3c, 0x9b, 0x3f, 0x9d, 0x9d, 0x61, 0xeb, 0x16, 0x32, 0xa1,
+	0x31, 0x3e, 0x99, 0x8f, 0xcf, 0x2c, 0x43, 0xe0, 0xd3, 0xf9, 0x64, 0x72, 0x82, 0x5f, 0x58, 0xb7,
+	0xc5, 0x66, 0xfe, 0x74, 0xf6, 0xe2, 0xf9, 0xd9, 0x43, 0xab, 0x86, 0xba, 0x60, 0x3e, 0xfe, 0x72,
+	0x3a, 0x7b, 0x36, 0xc6, 0x27, 0x13, 0xab, 0x8e, 0xde, 0x80, 0x3d, 0x19, 0xe3, 0x96, 0x60, 0xe3,
+	0xd4, 0x79, 0x75, 0x79, 0x64, 0xfc, 0x7e, 0x79, 0x64, 0xfc, 0x75, 0x79, 0x64, 0x7c, 0xd3, 0xf3,
+	0x99, 0x5b, 0x0a, 0x76, 0x95, 0xe0, 0x45, 0x53, 0xbe, 0xf6, 0x8f, 0xfe, 0x0e, 0x00, 0x00, 0xff,
+	0xff, 0x6d, 0x53, 0xc5, 0x1e, 0xdf, 0x09, 0x00, 0x00,
 }
 
 func (m *LabelPair) Marshal() (dAtA []byte, err error) {
@@ -1755,6 +1764,13 @@ func (m *MetricFamily) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 		i -= len(m.XXX_unrecognized)
 		copy(dAtA[i:], m.XXX_unrecognized)
 	}
+	if len(m.Unit) > 0 {
+		i -= len(m.Unit)
+		copy(dAtA[i:], m.Unit)
+		i = encodeVarintMetrics(dAtA, i, uint64(len(m.Unit)))
+		i--
+		dAtA[i] = 0x2a
+	}
 	if len(m.Metric) > 0 {
 		for iNdEx := len(m.Metric) - 1; iNdEx >= 0; iNdEx-- {
 			{
@@ -2128,6 +2144,10 @@ func (m *MetricFamily) Size() (n int) {
 			n += 1 + l + sovMetrics(uint64(l))
 		}
 	}
+	l = len(m.Unit)
+	if l > 0 {
+		n += 1 + l + sovMetrics(uint64(l))
+	}
 	if m.XXX_unrecognized != nil {
 		n += len(m.XXX_unrecognized)
 	}
@@ -4074,6 +4094,38 @@ func (m *MetricFamily) Unmarshal(dAtA []byte) error {
 				return err
 			}
 			iNdEx = postIndex
+		case 5:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Unit", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowMetrics
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthMetrics
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthMetrics
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Unit = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
 		default:
 			iNdEx = preIndex
 			skippy, err := skipMetrics(dAtA[iNdEx:])
diff --git a/prompb/io/prometheus/client/metrics.proto b/prompb/io/prometheus/client/metrics.proto
index 13ac8dcb4..06dcc34af 100644
--- a/prompb/io/prometheus/client/metrics.proto
+++ b/prompb/io/prometheus/client/metrics.proto
@@ -153,4 +153,5 @@ message MetricFamily {
   string          help   = 2;
   MetricType      type   = 3;
   repeated Metric metric = 4 [(gogoproto.nullable) = false];
+  string          unit   = 5;
 }