diff --git a/json5pp.hpp b/json5pp.hpp
index 8d12cc2..0bc987a 100644
--- a/json5pp.hpp
+++ b/json5pp.hpp
@@ -10,6 +10,7 @@
 #include <cmath>
 #include <limits>
 #include <streambuf>
+#include <cstdint>
 
 namespace json5pp {