diff --git a/Source/utils/format_int.hpp b/Source/utils/format_int.hpp
index cff0b9348..4a00b37b2 100644
--- a/Source/utils/format_int.hpp
+++ b/Source/utils/format_int.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <string>
 
 namespace devilution {