diff --git a/apps/wakunode2/external_config.nim b/apps/wakunode2/external_config.nim
index 3c604dafe1..ac0c5cd309 100644
--- a/apps/wakunode2/external_config.nim
+++ b/apps/wakunode2/external_config.nim
@@ -223,7 +223,7 @@ type
       name: "storenode" }: string
 
     storeMessageRetentionPolicy* {.
-      desc: "Message store retention policy. Time retention policy: 'time:<seconds>'. Capacity retention policy: 'capacity:<count>'. Set to 'none' to disable.",
+      desc: "Message store retention policy. Time retention policy: 'time:<seconds>'. Capacity retention policy: 'capacity:<count>'. Size retention policy: 'size:<xMB/xGB>'. Set to 'none' to disable.",
       defaultValue: "time:" & $2.days.seconds,
       name: "store-message-retention-policy" }: string