diff --git a/base64.h b/base64.h
index c3e3931..75d5550 100644
--- a/base64.h
+++ b/base64.h
@@ -1,5 +1,6 @@
 #ifndef _MACARON_BASE64_H_
 #define _MACARON_BASE64_H_
+#include <cstdint>
 
 #include <string>