diff --git a/csscolorparser.hpp b/csscolorparser.hpp
index 862afa2..6db7675 100644
--- a/csscolorparser.hpp
+++ b/csscolorparser.hpp
@@ -26,6 +26,7 @@
 #define CSS_COLOR_PARSER_CPP
 
 #include <string>
+#include <cstdint>
 
 namespace CSSColorParser {
 struct ConstColor {