diff --git a/include/String.hpp b/include/String.hpp
index 276ec1e..5e80f2e 100644
--- a/include/String.hpp
+++ b/include/String.hpp
@@ -6,6 +6,7 @@
 #include <stdexcept>
 #include <ostream>
 #include <istream>
+#include <cstdint>
 
 class String
 {