diff --git a/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_ROUTER_CONFIG.json5 b/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_ROUTER_CONFIG.json5
index 8e5eb983..cc4825bc 100644
--- a/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_ROUTER_CONFIG.json5
+++ b/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_ROUTER_CONFIG.json5
@@ -69,6 +69,8 @@
   timestamping: {
     /// Whether data messages should be timestamped if not already.
     /// Accepts a single boolean value or different values for router, peer and client.
+    /// PublicationCache which is required for transient_local durability
+    /// only works when time-stamping is enabled.
     enabled: { router: true, peer: true, client: false },
     /// Whether data messages with timestamps in the future should be dropped or not.
     /// If set to false (default), messages with timestamps in the future are retimestamped.
diff --git a/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_SESSION_CONFIG.json5 b/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_SESSION_CONFIG.json5
index 837896c0..df48b032 100644
--- a/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_SESSION_CONFIG.json5
+++ b/rmw_zenoh_cpp/config/DEFAULT_RMW_ZENOH_SESSION_CONFIG.json5
@@ -69,6 +69,8 @@
   timestamping: {
     /// Whether data messages should be timestamped if not already.
     /// Accepts a single boolean value or different values for router, peer and client.
+    /// PublicationCache which is required for transient_local durability
+    /// only works when time-stamping is enabled.
     enabled: { router: true, peer: true, client: false },
     /// Whether data messages with timestamps in the future should be dropped or not.
     /// If set to false (default), messages with timestamps in the future are retimestamped.