diff --git a/src/xmessage.cpp b/src/xmessage.cpp
index 1ab9544..5a14ba0 100644
--- a/src/xmessage.cpp
+++ b/src/xmessage.cpp
@@ -13,6 +13,7 @@
#include <sstream>
#include <string>
#include <utility>
+#include <ciso646>
#include "nlohmann/json.hpp"