diff --git a/example/cxxopts.hpp b/example/cxxopts.hpp

index 6fd170d..6906e3b 100644

--- a/example/cxxopts.hpp

+++ b/example/cxxopts.hpp

@@ -37,6 +37,7 @@ THE SOFTWARE.

 #include <unordered_map>

 #include <unordered_set>

 #include <vector>

+#include <limits>

 #ifdef __cpp_lib_optional

 #include <optional>