diff --git a/topics/lru-cache.md b/topics/lru-cache.md
index fccec2ba..5468ca46 100644
--- a/topics/lru-cache.md
+++ b/topics/lru-cache.md
@@ -57,6 +57,8 @@ The following policies are available:
 
 The policies **volatile-lru**, **volatile-lfu**, **volatile-random**, and **volatile-ttl** behave like **noeviction** if there are no keys to evict matching the prerequisites.
 
+**LRU**, **LFU** and **volatile-ttl** are implemented using approximated randomized algorithms.
+
 Picking the right eviction policy is important depending on the access pattern
 of your application, however you can reconfigure the policy at runtime while
 the application is running, and monitor the number of cache misses and hits