diff --git a/src/script/conversation/ConversationRepository.ts b/src/script/conversation/ConversationRepository.ts
index af270b65a6e..01a66f16893 100644
--- a/src/script/conversation/ConversationRepository.ts
+++ b/src/script/conversation/ConversationRepository.ts
@@ -2255,7 +2255,7 @@ export class ConversationRepository {
    */
   private async clearConversationContent(conversation: Conversation, timestamp: number) {
     await this.deleteMessages(conversation, timestamp);
-    await this.addCreationMessage(conversation, !!this.userState.self()?.isTemporaryGuest(), timestamp);
+    await this.addCreationMessage(conversation, !!this.userState.self()?.isTemporaryGuest());
     conversation.setTimestamp(timestamp, Conversation.TIMESTAMP_TYPE.CLEARED);
   }
 
diff --git a/src/script/conversation/EventBuilder.ts b/src/script/conversation/EventBuilder.ts
index b122cb8982f..b6d80ede2c8 100644
--- a/src/script/conversation/EventBuilder.ts
+++ b/src/script/conversation/EventBuilder.ts
@@ -430,11 +430,11 @@ export const EventBuilder = {
   buildGroupCreation(
     conversationEntity: Conversation,
     isTemporaryGuest: boolean = false,
-    timestamp: number,
+    timestamp: number = 0,
   ): GroupCreationEvent {
     const {creator: creatorId} = conversationEntity;
     const selfUserId = conversationEntity.selfUser().id;
-    const isoDate = new Date(timestamp || 0).toISOString();
+    const isoDate = new Date(timestamp).toISOString();
 
     const userIds = conversationEntity.participating_user_ids().slice();
     const createdBySelf = creatorId === selfUserId || isTemporaryGuest;