diff --git a/relay-reactjs-chat/package.json b/relay-reactjs-chat/package.json
index ad799de..dc96e3e 100644
--- a/relay-reactjs-chat/package.json
+++ b/relay-reactjs-chat/package.json
@@ -7,7 +7,7 @@
     "@testing-library/jest-dom": "^5.16.5",
     "@testing-library/react": "^13.3.0",
     "@testing-library/user-event": "^13.5.0",
-    "js-waku": "0.28.0",
+    "js-waku": "0.28.1",
     "protobufjs": "^7.0.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
diff --git a/relay-reactjs-chat/pnpm-lock.yaml b/relay-reactjs-chat/pnpm-lock.yaml
index d159df5..53a7bcd 100644
--- a/relay-reactjs-chat/pnpm-lock.yaml
+++ b/relay-reactjs-chat/pnpm-lock.yaml
@@ -6,7 +6,7 @@ specifiers:
   '@testing-library/react': ^13.3.0
   '@testing-library/user-event': ^13.5.0
   eslint: ^8.22.0
-  js-waku: 0.28.0
+  js-waku: 0.28.1
   protobufjs: ^7.0.0
   react: ^18.2.0
   react-dom: ^18.2.0
@@ -17,7 +17,7 @@ dependencies:
   '@testing-library/jest-dom': 5.16.5
   '@testing-library/react': 13.3.0_biqbaboplfbrettd7655fr4n2y
   '@testing-library/user-event': 13.5.0_wl4iynrlixafokvgqnhzlvigei
-  js-waku: 0.28.0_undici@5.10.0
+  js-waku: 0.28.1_undici@5.10.0
   protobufjs: 7.0.0
   react: 18.2.0
   react-dom: 18.2.0_react@18.2.0
@@ -7001,8 +7001,8 @@ packages:
   /js-tokens/4.0.0:
     resolution: {integrity: sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ==}
 
-  /js-waku/0.28.0_undici@5.10.0:
-    resolution: {integrity: sha512-MEIFugvio2IaQMQT+g+bn24BvlJ5S4PdSKD0AGVZlR7q1BhECwlpRoytyz0A/hC1+EJWhrZB8cpIAmxwtYWTBw==}
+  /js-waku/0.28.1_undici@5.10.0:
+    resolution: {integrity: sha512-0h9TpV6jywyjdes8hr9tFV/5iJh3LQN3sQFYHcXyi4cK+4htNiMrCRjBSqRBtfhs/j+4tOkrht8gRJRLHdA5RA==}
     engines: {node: '>=16'}
     dependencies:
       '@chainsafe/libp2p-gossipsub': 4.1.1_undici@5.10.0
diff --git a/relay-reactjs-chat/src/App.js b/relay-reactjs-chat/src/App.js
index 7601b22..e0e7ce9 100644
--- a/relay-reactjs-chat/src/App.js
+++ b/relay-reactjs-chat/src/App.js
@@ -52,12 +52,12 @@ function App() {
     if (!waku) return;
 
     // Pass the content topic to only process messages related to your dApp
-    waku.relay.addObserver(processIncomingMessage, [ContentTopic]);
+    const deleteObserver = waku.relay.addObserver(processIncomingMessage, [
+      ContentTopic,
+    ]);
 
-    // `cleanUp` is called when the component is unmounted, see ReactJS doc.
-    return function cleanUp() {
-      waku.relay.deleteObserver(processIncomingMessage, [ContentTopic]);
-    };
+    // Called when the component is unmounted, see ReactJS doc.
+    return deleteObserver;
   }, [waku, wakuStatus, processIncomingMessage]);
 
   const sendMessageOnClick = () => {