diff --git a/gumpp.hpp b/gumpp.hpp
index bcebb88..c39ba9e 100644
--- a/gumpp.hpp
+++ b/gumpp.hpp
@@ -24,6 +24,7 @@
 #include <vector>
 #include <string>
 #include <optional>
+#include <cinttypes>
 #if defined(_MSC_VER)
 #include <BaseTsd.h>
 typedef SSIZE_T ssize_t;