diff --git a/extra/lru-cache/lru-cache.factor b/extra/lru-cache/lru-cache.factor
index 54e39c847f..e7d82e2da1 100644
--- a/extra/lru-cache/lru-cache.factor
+++ b/extra/lru-cache/lru-cache.factor
@@ -31,3 +31,7 @@ M: lru-cache set-at
             [ dlist>> ] tri (delete-at)
         ] [ drop ] if
     ] [ drop ] if* ;
+
+M: lru-cache clone
+    [ assoc>> clone ] [ dlist>> clone ] [ max-size>> ] tri
+    lru-cache boa ;