diff --git a/cpp/piscsi/piscsi_service.cpp b/cpp/piscsi/piscsi_service.cpp
index 897f250b91..700a86588e 100644
--- a/cpp/piscsi/piscsi_service.cpp
+++ b/cpp/piscsi/piscsi_service.cpp
@@ -122,7 +122,7 @@ PbCommand PiscsiService::ReadCommand(CommandContext& context) const
 	PbCommand command;
 
 	// Read magic string
-	vector<byte> magic(6);
+	array<byte, 6> magic;
 	const size_t bytes_read = context.GetSerializer().ReadBytes(fd, magic);
 	if (!bytes_read) {
 		return command;
diff --git a/cpp/shared/protobuf_serializer.cpp b/cpp/shared/protobuf_serializer.cpp
index ffca4e23b5..2c0599299a 100644
--- a/cpp/shared/protobuf_serializer.cpp
+++ b/cpp/shared/protobuf_serializer.cpp
@@ -3,7 +3,7 @@
 // SCSI Target Emulator PiSCSI
 // for Raspberry Pi
 //
-// Copyright (C) 2022 Uwe Seimet
+// Copyright (C) 2022-2023 Uwe Seimet
 //
 //---------------------------------------------------------------------------
 
@@ -42,7 +42,7 @@ void ProtobufSerializer::SerializeMessage(int fd, const google::protobuf::Messag
 void ProtobufSerializer::DeserializeMessage(int fd, google::protobuf::Message& message) const
 {
 	// Read the header with the size of the protobuf data
-	vector<byte> header_buf(4);
+	array<byte, 4> header_buf;
 	if (ReadBytes(fd, header_buf) < header_buf.size()) {
 		throw io_exception("Invalid protobuf message header");
 	}
@@ -64,7 +64,7 @@ void ProtobufSerializer::DeserializeMessage(int fd, google::protobuf::Message& m
 	message.ParseFromString(data);
 }
 
-size_t ProtobufSerializer::ReadBytes(int fd, vector<byte>& buf) const
+size_t ProtobufSerializer::ReadBytes(int fd, span<byte> buf) const
 {
 	size_t offset = 0;
 	while (offset < buf.size()) {
diff --git a/cpp/shared/protobuf_serializer.h b/cpp/shared/protobuf_serializer.h
index b9a6730232..d4b2c18ef5 100644
--- a/cpp/shared/protobuf_serializer.h
+++ b/cpp/shared/protobuf_serializer.h
@@ -3,7 +3,7 @@
 // SCSI Target Emulator PiSCSI
 // for Raspberry Pi
 //
-// Copyright (C) 2022 Uwe Seimet
+// Copyright (C) 2022-2023 Uwe Seimet
 //
 // Helper for serializing/deserializing protobuf messages
 //
@@ -12,7 +12,7 @@
 #pragma once
 
 #include "google/protobuf/message.h"
-#include <vector>
+#include <span>
 
 using namespace std;
 
@@ -25,5 +25,5 @@ class ProtobufSerializer
 
 	void SerializeMessage(int, const google::protobuf::Message&) const;
 	void DeserializeMessage(int, google::protobuf::Message&) const;
-	size_t ReadBytes(int, vector<byte>&) const;
+	size_t ReadBytes(int, span<byte>) const;
 };