diff --git a/src/libutil/lru-cache.hh b/src/libutil/lru-cache.hh
index 8b83f842c..6ef4a3e06 100644
--- a/src/libutil/lru-cache.hh
+++ b/src/libutil/lru-cache.hh
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cassert>
 #include <map>
 #include <list>
 #include <optional>