diff --git a/src/libutil/finally.hh b/src/libutil/finally.hh
index db654301f..4cae20a36 100644
--- a/src/libutil/finally.hh
+++ b/src/libutil/finally.hh
@@ -1,11 +1,13 @@
 #pragma once
 ///@file
 
+#include <utility>
+
 /**
  * A trivial class to run a function at the end of a scope.
  */
 template<typename Fn>
-class Finally
+class [[nodiscard("Finally values must be used")]] Finally
 {
 private:
     Fn fun;