diff --git a/include/cxxopts.hpp b/include/cxxopts.hpp
index 991ba3fc..a2e71faf 100644
--- a/include/cxxopts.hpp
+++ b/include/cxxopts.hpp
@@ -27,6 +27,7 @@ THE SOFTWARE.
 #ifndef CXXOPTS_HPP_INCLUDED
 #define CXXOPTS_HPP_INCLUDED
 
+#include <cstdint>
 #include <cstdlib>
 #include <cstring>
 #include <exception>