diff --git a/object/grpc/service.go b/object/grpc/service.go
index 74dc168..44b5f4a 100644
--- a/object/grpc/service.go
+++ b/object/grpc/service.go
@@ -109,7 +109,7 @@ func (m *PutRequest_Body_Init) SetHeader(v *Header) {
 }
 
 // SetCopiesNumber sets number of the copies to save.
-func (m *PutRequest_Body_Init) SetCopiesNumber(v []uint32) {
+func (m *PutRequest_Body_Init) SetCopiesNumber(v uint32) {
 	m.CopiesNumber = v
 }
 
diff --git a/object/grpc/service.pb.go b/object/grpc/service.pb.go
index 6ba4090..207b0b0 100644
--- a/object/grpc/service.pb.go
+++ b/object/grpc/service.pb.go
@@ -1452,17 +1452,9 @@ type PutRequest_Body_Init struct {
 	Signature *grpc1.Signature `protobuf:"bytes,2,opt,name=signature,proto3" json:"signature,omitempty"`
 	// Object's Header
 	Header *Header `protobuf:"bytes,3,opt,name=header,proto3" json:"header,omitempty"`
-	// Number of copies of the object to store within the RPC call. By default,
+	// Number of the object copies to store within the RPC call. By default
 	// object is processed according to the container's placement policy.
-	// Can be one of:
-	// 1. A single number; applied to the whole request and is treated as
-	// a minimal number of nodes that must store an object to complete the
-	// request successfully.
-	// 2. An ordered array; every number is treated as a minimal number of
-	// nodes in a corresponding placement vector that must store an object
-	// to complete the request successfully. The length MUST equal the placement
-	// vectors number, otherwise request is considered malformed.
-	CopiesNumber []uint32 `protobuf:"varint,4,rep,packed,name=copies_number,json=copiesNumber,proto3" json:"copies_number,omitempty"`
+	CopiesNumber uint32 `protobuf:"varint,4,opt,name=copies_number,json=copiesNumber,proto3" json:"copies_number,omitempty"`
 }
 
 func (x *PutRequest_Body_Init) Reset() {
@@ -1518,11 +1510,11 @@ func (x *PutRequest_Body_Init) GetHeader() *Header {
 	return nil
 }
 
-func (x *PutRequest_Body_Init) GetCopiesNumber() []uint32 {
+func (x *PutRequest_Body_Init) GetCopiesNumber() uint32 {
 	if x != nil {
 		return x.CopiesNumber
 	}
-	return nil
+	return 0
 }
 
 // PUT Object response body
@@ -2465,7 +2457,7 @@ var file_object_grpc_service_proto_rawDesc = []byte{
 	0x65, 0x72, 0x18, 0x03, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x18, 0x2e, 0x6e, 0x65, 0x6f, 0x2e, 0x66,
 	0x73, 0x2e, 0x76, 0x32, 0x2e, 0x6f, 0x62, 0x6a, 0x65, 0x63, 0x74, 0x2e, 0x48, 0x65, 0x61, 0x64,
 	0x65, 0x72, 0x52, 0x06, 0x68, 0x65, 0x61, 0x64, 0x65, 0x72, 0x12, 0x23, 0x0a, 0x0d, 0x63, 0x6f,
-	0x70, 0x69, 0x65, 0x73, 0x5f, 0x6e, 0x75, 0x6d, 0x62, 0x65, 0x72, 0x18, 0x04, 0x20, 0x03, 0x28,
+	0x70, 0x69, 0x65, 0x73, 0x5f, 0x6e, 0x75, 0x6d, 0x62, 0x65, 0x72, 0x18, 0x04, 0x20, 0x01, 0x28,
 	0x0d, 0x52, 0x0c, 0x63, 0x6f, 0x70, 0x69, 0x65, 0x73, 0x4e, 0x75, 0x6d, 0x62, 0x65, 0x72, 0x42,
 	0x0d, 0x0a, 0x0b, 0x6f, 0x62, 0x6a, 0x65, 0x63, 0x74, 0x5f, 0x70, 0x61, 0x72, 0x74, 0x22, 0xa0,
 	0x02, 0x0a, 0x0b, 0x50, 0x75, 0x74, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x12, 0x36,
diff --git a/object/marshal.go b/object/marshal.go
index 7a89b97..b918e69 100644
--- a/object/marshal.go
+++ b/object/marshal.go
@@ -516,7 +516,7 @@ func (r *PutObjectPartInit) StableMarshal(buf []byte) []byte {
 	offset += proto.NestedStructureMarshal(putReqInitObjectIDField, buf[offset:], r.id)
 	offset += proto.NestedStructureMarshal(putReqInitSignatureField, buf[offset:], r.sig)
 	offset += proto.NestedStructureMarshal(putReqInitHeaderField, buf[offset:], r.hdr)
-	proto.RepeatedUInt32Marshal(putReqInitCopiesNumField, buf[offset:], r.copyNum)
+	proto.UInt32Marshal(putReqInitCopiesNumField, buf[offset:], r.copyNum)
 
 	return buf
 }
@@ -529,9 +529,7 @@ func (r *PutObjectPartInit) StableSize() (size int) {
 	size += proto.NestedStructureSize(putReqInitObjectIDField, r.id)
 	size += proto.NestedStructureSize(putReqInitSignatureField, r.sig)
 	size += proto.NestedStructureSize(putReqInitHeaderField, r.hdr)
-
-	arrSize, _ := proto.RepeatedUInt32Size(putReqInitCopiesNumField, r.copyNum)
-	size += arrSize
+	size += proto.UInt32Size(putReqInitCopiesNumField, r.copyNum)
 
 	return size
 }
diff --git a/object/test/generate.go b/object/test/generate.go
index 32d7a3c..0816ffc 100644
--- a/object/test/generate.go
+++ b/object/test/generate.go
@@ -216,7 +216,7 @@ func GeneratePutObjectPartInit(empty bool) *object.PutObjectPartInit {
 	m := new(object.PutObjectPartInit)
 
 	if !empty {
-		m.SetCopiesNumber([]uint32{234})
+		m.SetCopiesNumber(234)
 		m.SetObjectID(refstest.GenerateObjectID(false))
 	}
 
diff --git a/object/types.go b/object/types.go
index a40de57..f076b74 100644
--- a/object/types.go
+++ b/object/types.go
@@ -128,7 +128,7 @@ type PutObjectPartInit struct {
 
 	hdr *Header
 
-	copyNum []uint32
+	copyNum uint32
 }
 
 type PutObjectPartChunk struct {
@@ -894,15 +894,15 @@ func (r *PutObjectPartInit) SetHeader(v *Header) {
 	r.hdr = v
 }
 
-func (r *PutObjectPartInit) GetCopiesNumber() []uint32 {
+func (r *PutObjectPartInit) GetCopiesNumber() uint32 {
 	if r != nil {
 		return r.copyNum
 	}
 
-	return nil
+	return 0
 }
 
-func (r *PutObjectPartInit) SetCopiesNumber(v []uint32) {
+func (r *PutObjectPartInit) SetCopiesNumber(v uint32) {
 	r.copyNum = v
 }