diff --git a/packages/status-communities/src/chat.ts b/packages/status-communities/src/chat.ts
index 20abeb14..e08e3a22 100644
--- a/packages/status-communities/src/chat.ts
+++ b/packages/status-communities/src/chat.ts
@@ -14,7 +14,7 @@ export class Chat {
   /**
    * Create a public chat room.
    */
-  public static async create(id: string) {
+  public static async create(id: string): Promise<Chat> {
     const symKey = await createSymKeyFromPassword(id);
 
     return new Chat(id, symKey);
@@ -34,7 +34,7 @@ export class Chat {
     return message;
   }
 
-  public handleNewMessage(message: ChatMessage) {
+  public handleNewMessage(message: ChatMessage): void {
     this._updateClockFromMessage(message);
   }
 
@@ -52,11 +52,18 @@ export class Chat {
   }
 
   private _updateClockFromMessage(message: ChatMessage): void {
-    if (!this.lastMessage || this.lastMessage.clock <= message.clock) {
+    if (
+      !this.lastMessage ||
+      !this.lastMessage.clock ||
+      (message.clock && this.lastMessage.clock <= message.clock)
+    ) {
       this.lastMessage = message;
     }
 
-    if (!this.lastClockValue || this.lastClockValue < message.clock) {
+    if (
+      !this.lastClockValue ||
+      (message.clock && this.lastClockValue < message.clock)
+    ) {
       this.lastClockValue = message.clock;
     }
   }
diff --git a/packages/status-communities/src/chat_message.ts b/packages/status-communities/src/chat_message.ts
index 31129b1d..e24d25ac 100644
--- a/packages/status-communities/src/chat_message.ts
+++ b/packages/status-communities/src/chat_message.ts
@@ -15,7 +15,7 @@ export class ChatMessage {
     timestamp: number,
     text: string,
     chatId: string
-  ) {
+  ): ChatMessage {
     const proto = {
       clock, // ms?
       timestamp, //ms?
@@ -50,7 +50,7 @@ export class ChatMessage {
     return proto.ChatMessage.encode(this.proto).finish();
   }
 
-  public get clock() {
+  public get clock(): number | undefined {
     return this.proto.clock;
   }
 
diff --git a/packages/status-communities/src/messenger.ts b/packages/status-communities/src/messenger.ts
index 68503d9c..d5fe484c 100644
--- a/packages/status-communities/src/messenger.ts
+++ b/packages/status-communities/src/messenger.ts
@@ -28,7 +28,7 @@ export class Messenger {
   public static async create(
     identity: Identity,
     wakuOptions?: WakuCreateOptions
-  ) {
+  ): Promise<Messenger> {
     const _wakuOptions = Object.assign({ bootstrap: true }, wakuOptions);
     const waku = await Waku.create(_wakuOptions);
     return new Messenger(identity, waku);
@@ -39,7 +39,7 @@ export class Messenger {
    *
    * Use `addListener` to get messages received on this chat.
    */
-  public async joinChat(chatId: string) {
+  public async joinChat(chatId: string): Promise<void> {
     if (this.chatsById.has(chatId))
       throw `Failed to join chat, it is already joined: ${chatId}`;
 
@@ -102,7 +102,7 @@ export class Messenger {
   public addObserver(
     observer: (message: ApplicationMetadataMessage) => void,
     chatId: string
-  ) {
+  ): void {
     // Not sure this is the best design here. Maybe `addObserver` and `joinChat` should be merged.
 
     if (!this.chatsById.has(chatId))
@@ -153,7 +153,7 @@ export class Messenger {
     if (!chat)
       throw `Failed to retrieve messages, chat is not joined: ${chatId}`;
 
-    const _callback = (wakuMessages: WakuMessage[]) => {
+    const _callback = (wakuMessages: WakuMessage[]): void => {
       const isDefined = (
         msg: ApplicationMetadataMessage | undefined
       ): msg is ApplicationMetadataMessage => {
@@ -187,7 +187,7 @@ export class Messenger {
   private _handleNewChatMessage(
     chat: Chat,
     message: ApplicationMetadataMessage
-  ) {
+  ): void {
     if (!message.payload || !message.type || !message.signature) return;
 
     const chatMessage = ChatMessage.decode(message.payload);