1 files changed, 5 insertions, 0 deletions
diff --git a/args.hxx b/args.hxx
index 7be2305..da93fa1 100644
--- a/args.hxx
+++ b/args.hxx
@@ -25,6 +25,9 @@
  * The important stuff is done inside the args namespace
  */
 
+#ifndef ARGS_HXX
+#define ARGS_HXX
+
 #include <algorithm>
 #include <exception>
 #include <functional>
@@ -2051,3 +2054,5 @@ namespace args
             }
     };
 }
+
+#endif