diff --git a/util/proto/marshal.go b/util/proto/marshal.go
index e345492..b1f55a3 100644
--- a/util/proto/marshal.go
+++ b/util/proto/marshal.go
@@ -20,13 +20,21 @@ type (
 )
 
 func BytesMarshal(field int, buf, v []byte) int {
-	if len(v) == 0 {
-		return 0
-	}
 	return bytesMarshal(field, buf, v)
 }
 
-func bytesMarshal(field int, buf, v []byte) int {
+func BytesSize(field int, v []byte) int {
+	return bytesSize(field, v)
+}
+
+func bytesMarshal[T ~[]byte | ~string](field int, buf []byte, v T) int {
+	if len(v) == 0 {
+		return 0
+	}
+	return bytesMarshalNoCheck(field, buf, v)
+}
+
+func bytesMarshalNoCheck[T ~[]byte | ~string](field int, buf []byte, v T) int {
 	prefix := field<<3 | 0x2
 
 	// buf length check can prevent panic at PutUvarint, but it will make
@@ -38,26 +46,25 @@ func bytesMarshal(field int, buf, v []byte) int {
 	return i
 }
 
-func BytesSize(field int, v []byte) int {
-	ln := len(v)
-	if ln == 0 {
+func bytesSize[T ~[]byte | ~string](field int, v T) int {
+	if len(v) == 0 {
 		return 0
 	}
-	return bytesSize(field, v)
+	return bytesSizeNoCheck(field, v)
 }
 
-func bytesSize(field int, v []byte) int {
+func bytesSizeNoCheck[T ~[]byte | ~string](field int, v T) int {
 	prefix := field<<3 | 0x2
 
 	return VarUIntSize(uint64(prefix)) + VarUIntSize(uint64(len(v))) + len(v)
 }
 
 func StringMarshal(field int, buf []byte, v string) int {
-	return BytesMarshal(field, buf, []byte(v))
+	return bytesMarshal(field, buf, v)
 }
 
 func StringSize(field int, v string) int {
-	return BytesSize(field, []byte(v))
+	return bytesSize(field, v)
 }
 
 func BoolMarshal(field int, buf []byte, v bool) int {
@@ -146,7 +153,7 @@ func RepeatedBytesMarshal(field int, buf []byte, v [][]byte) int {
 	var offset int
 
 	for i := range v {
-		offset += bytesMarshal(field, buf[offset:], v[i])
+		offset += bytesMarshalNoCheck(field, buf[offset:], v[i])
 	}
 
 	return offset
@@ -154,7 +161,7 @@ func RepeatedBytesMarshal(field int, buf []byte, v [][]byte) int {
 
 func RepeatedBytesSize(field int, v [][]byte) (size int) {
 	for i := range v {
-		size += bytesSize(field, v[i])
+		size += bytesSizeNoCheck(field, v[i])
 	}
 
 	return size
@@ -164,7 +171,7 @@ func RepeatedStringMarshal(field int, buf []byte, v []string) int {
 	var offset int
 
 	for i := range v {
-		offset += bytesMarshal(field, buf[offset:], []byte(v[i]))
+		offset += bytesMarshalNoCheck(field, buf[offset:], v[i])
 	}
 
 	return offset
@@ -172,7 +179,7 @@ func RepeatedStringMarshal(field int, buf []byte, v []string) int {
 
 func RepeatedStringSize(field int, v []string) (size int) {
 	for i := range v {
-		size += bytesSize(field, []byte(v[i]))
+		size += bytesSizeNoCheck(field, v[i])
 	}
 
 	return size