diff --git a/include/kvm_websocket.hpp b/include/kvm_websocket.hpp
index a9dc8ea..51246aa 100644
--- a/include/kvm_websocket.hpp
+++ b/include/kvm_websocket.hpp
@@ -145,8 +145,8 @@
 
     crow::websocket::Connection& conn;
     boost::asio::ip::tcp::socket hostSocket;
-    boost::beast::flat_static_buffer<1024U * 50U> outputBuffer;
-    boost::beast::flat_static_buffer<1024U> inputBuffer;
+    boost::beast::flat_static_buffer<1024UL * 50UL> outputBuffer;
+    boost::beast::flat_static_buffer<1024UL> inputBuffer;
     bool doingWrite;
 };