diff --git a/session/marshal.go b/session/marshal.go
index 8632398..cda9579 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.NestedStructureMarshalUnchecked(objectCtxTargetField, buf[offset:], objectSessionContextTarget{
+	proto.NestedStructureMarshal(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.NestedStructureSizeUnchecked(objectCtxTargetField, objectSessionContextTarget{
+	size += proto.NestedStructureSize(objectCtxTargetField, objectSessionContextTarget{
 		cnr:  c.cnr,
 		objs: c.objs,
 	})
diff --git a/util/proto/marshal.go b/util/proto/marshal.go
index c4f3a78..606086a 100644
--- a/util/proto/marshal.go
+++ b/util/proto/marshal.go
@@ -249,21 +249,12 @@ func VarUIntSize(x uint64) int {
 	return (bits.Len64(x|1) + 6) / 7
 }
 
-type ptrStableMarshaler[T any] interface {
-	stableMarshaller
-	~*T
-}
-
-func NestedStructureMarshal[T any, M ptrStableMarshaler[T]](field int64, buf []byte, v M) int {
-	if v == nil {
+func NestedStructureMarshal[T stableMarshaller](field int64, buf []byte, v T) int {
+	n := v.StableSize()
+	if n == 0 {
 		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))
@@ -272,17 +263,13 @@ func NestedStructureMarshalUnchecked[T stableMarshaller](field int64, buf []byte
 	return offset + n
 }
 
-func NestedStructureSize[T any, M ptrStableMarshaler[T]](field int64, v M) (size int) {
-	if v == nil {
+func NestedStructureSize[T stableMarshaller](field int64, v T) (size int) {
+	n := v.StableSize()
+	if n == 0 {
 		return 0
 	}
-
-	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))
+	size = protowire.SizeGroup(protowire.Number(field), protowire.SizeBytes(n))
+	return
 }
 
 func Fixed64Marshal(field int, buf []byte, v uint64) int {