diff --git a/include/stdplus/variant.hpp b/include/stdplus/variant.hpp
index 8a1f3e9..47a3016 100644
--- a/include/stdplus/variant.hpp
+++ b/include/stdplus/variant.hpp
@@ -1,3 +1,4 @@
+#pragma once
 #include <stdplus/concepts.hpp>
 
 #include <concepts>