diff --git a/src/state.hpp b/src/state.hpp
index 61795c5b..fe7cf44d 100644
--- a/src/state.hpp
+++ b/src/state.hpp
@@ -1,6 +1,7 @@
 #include "branches2.hpp"
 #include "func_create_base.hpp"
 
+#include <memory>
 
 class State
 {