diff --git a/include/m17cxx/Util.h b/include/m17cxx/Util.h
index 7aca344..f29ace8 100644
--- a/include/m17cxx/Util.h
+++ b/include/m17cxx/Util.h
@@ -3,6 +3,7 @@
 #pragma once
 
 #include <algorithm>
+#include <cstdint>
 #include <cstdlib>
 #include <cassert>
 #include <array>