diff --git a/power-sequencer/types.hpp b/power-sequencer/types.hpp
index 78b5ea7..c473828 100644
--- a/power-sequencer/types.hpp
+++ b/power-sequencer/types.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <functional>
 #include <map>
 #include <string>
 #include <tuple>