diff --git a/src/channel.ts b/src/channel.ts
index ffb9cdadc..c7edbd4ed 100644
--- a/src/channel.ts
+++ b/src/channel.ts
@@ -707,7 +707,7 @@ export class Channel<StreamChatGenerics extends ExtendableGenerics = DefaultGene
    *
    * @return {ReturnType<ChannelState<StreamChatGenerics>['formatMessage']> | undefined} Description
    */
-  lastMessage() {
+  lastMessage(): FormatMessageResponse<StreamChatGenerics> | undefined {
     // get last 5 messages, sort, return the latest
     // get a slice of the last 5
     let min = this.state.latestMessages.length - 5;