diff --git a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/AggregatedReactionSender.kt b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/AggregatedReactionSender.kt
index 6dc77b545f..cce557d0ec 100644
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/AggregatedReactionSender.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/model/AggregatedReactionSender.kt
@@ -7,10 +7,13 @@
 
 package io.element.android.features.messages.impl.timeline.model
 
+import androidx.compose.runtime.Immutable
 import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.user.MatrixUser
 import java.util.Date
 
+// Need to be marked as @Immutable for Date
+@Immutable
 data class AggregatedReactionSender(
     val senderId: UserId,
     val timestamp: Date,