diff --git a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/TimelineItem.kt b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/TimelineItem.kt
index 8f00dfb0dd..bd3090e390 100644
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/TimelineItem.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/TimelineItem.kt
@@ -54,6 +54,7 @@ sealed interface TimelineItem {
     @Immutable
     data class Event(
         val id: String,
+        // Note: eventId can be null when the event is a local echo
         val eventId: EventId? = null,
         val transactionId: TransactionId? = null,
         val senderId: UserId,