diff --git a/session/marshal.go b/session/marshal.go
index cda9579..8632398 100644
--- a/session/marshal.go
+++ b/session/marshal.go
@@ -211,7 +211,7 @@ func (c *ObjectSessionContext) StableMarshal(buf []byte) []byte {
 	}
 
 	offset := proto.EnumMarshal(objectCtxVerbField, buf, int32(c.verb))
-	proto.NestedStructureMarshal(objectCtxTargetField, buf[offset:], objectSessionContextTarget{
+	proto.NestedStructureMarshalUnchecked(objectCtxTargetField, buf[offset:], objectSessionContextTarget{
 		cnr:  c.cnr,
 		objs: c.objs,
 	})
@@ -225,7 +225,7 @@ func (c *ObjectSessionContext) StableSize() (size int) {
 	}
 
 	size += proto.EnumSize(objectCtxVerbField, int32(c.verb))
-	size += proto.NestedStructureSize(objectCtxTargetField, objectSessionContextTarget{
+	size += proto.NestedStructureSizeUnchecked(objectCtxTargetField, objectSessionContextTarget{
 		cnr:  c.cnr,
 		objs: c.objs,
 	})
diff --git a/util/proto/marshal.go b/util/proto/marshal.go
index b16375a..2704960 100644
--- a/util/proto/marshal.go
+++ b/util/proto/marshal.go
@@ -20,9 +20,10 @@ type (
 		StableSize() int
 	}
 
-	setMarshalData interface {
+	setMarshalData[T any] interface {
 		SetMarshalData([]byte)
 		StableSize() int
+		~*T
 	}
 )
 
@@ -254,12 +255,21 @@ func VarUIntSize(x uint64) int {
 	return (bits.Len64(x|1) + 6) / 7
 }
 
-func NestedStructureMarshal[T stableMarshaller](field int64, buf []byte, v T) int {
-	n := v.StableSize()
-	if n == 0 {
+type ptrStableMarshaler[T any] interface {
+	stableMarshaller
+	~*T
+}
+
+func NestedStructureMarshal[T any, M ptrStableMarshaler[T]](field int64, buf []byte, v M) int {
+	if v == nil {
 		return 0
 	}
 
+	return NestedStructureMarshalUnchecked(field, buf, v)
+}
+
+func NestedStructureMarshalUnchecked[T stableMarshaller](field int64, buf []byte, v T) int {
+	n := v.StableSize()
 	prefix := protowire.EncodeTag(protowire.Number(field), protowire.BytesType)
 	offset := binary.PutUvarint(buf, prefix)
 	offset += binary.PutUvarint(buf[offset:], uint64(n))
@@ -272,12 +282,12 @@ func NestedStructureMarshal[T stableMarshaller](field int64, buf []byte, v T) in
 // and calls SetMarshalData for nested structure.
 //
 // Returns marshalled data length of nested structure.
-func NestedStructureSetMarshalData(field int64, parentData []byte, v setMarshalData) int {
-	n := v.StableSize()
-	if n == 0 {
+func NestedStructureSetMarshalData[T any, M setMarshalData[T]](field int64, parentData []byte, v M) int {
+	if v == nil {
 		return 0
 	}
 
+	n := v.StableSize()
 	buf := make([]byte, binary.MaxVarintLen64)
 	prefix := protowire.EncodeTag(protowire.Number(field), protowire.BytesType)
 	offset := binary.PutUvarint(buf, prefix)
@@ -288,13 +298,17 @@ func NestedStructureSetMarshalData(field int64, parentData []byte, v setMarshalD
 	return offset + n
 }
 
-func NestedStructureSize[T stableMarshaller](field int64, v T) (size int) {
-	n := v.StableSize()
-	if n == 0 {
+func NestedStructureSize[T any, M ptrStableMarshaler[T]](field int64, v M) (size int) {
+	if v == nil {
 		return 0
 	}
-	size = protowire.SizeGroup(protowire.Number(field), protowire.SizeBytes(n))
-	return
+
+	return NestedStructureSizeUnchecked(field, v)
+}
+
+func NestedStructureSizeUnchecked[T stableMarshaller](field int64, v T) int {
+	n := v.StableSize()
+	return protowire.SizeGroup(protowire.Number(field), protowire.SizeBytes(n))
 }
 
 func Fixed64Marshal(field int, buf []byte, v uint64) int {