diff --git a/tools/io_interface.hpp b/tools/io_interface.hpp
index cdc81ad..b31bdf9 100644
--- a/tools/io_interface.hpp
+++ b/tools/io_interface.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <cstdint>
+#include <cstdlib>
 
 namespace host_tool
 {