diff --git a/include/glim/util/callback_slot.hpp b/include/glim/util/callback_slot.hpp
index 908068ff..b1189711 100644
--- a/include/glim/util/callback_slot.hpp
+++ b/include/glim/util/callback_slot.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <vector>
+#include <algorithm>
 #include <functional>
 
 /**