diff --git a/lib/src/format.h b/lib/src/format.h
index ba5b831..c5b9224 100644
--- a/lib/src/format.h
+++ b/lib/src/format.h
@@ -4,6 +4,7 @@
 #include <string>
 #include <iostream>
 #include <iomanip>
+#include <cstdint>
 #include "sourcecode.h"
 
 namespace f2b