diff --git a/msl_verify.hpp b/msl_verify.hpp
index 3f6983e..af0c2a2 100644
--- a/msl_verify.hpp
+++ b/msl_verify.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <string>
 
 namespace minimum_ship_level