diff --git a/include/xlnt/utils/variant.hpp b/include/xlnt/utils/variant.hpp
index 21362578..0f47234a 100644
--- a/include/xlnt/utils/variant.hpp
+++ b/include/xlnt/utils/variant.hpp
@@ -25,6 +25,7 @@
 
 #include <string>
 #include <vector>
+#include <cstdint>
 
 #include <xlnt/xlnt_config.hpp>