diff --git a/src/openrct2/core/String.hpp b/src/openrct2/core/String.hpp
index 496a1f4c82..97d43173df 100644
--- a/src/openrct2/core/String.hpp
+++ b/src/openrct2/core/String.hpp
@@ -16,7 +16,7 @@
 
 #pragma once
 
-#include <stdarg.h>
+#include <cstdarg>
 #include <string>
 #include <vector>
 #include "../common.h"