diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0ab42df7..79a9ee8f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -39,6 +39,7 @@ Thanks to: @dathbe.
 - [weather] Fixed handling of empty values in weathergov providers handling of precipitationAmount (#3859)
 - [calendar] Fix regression handling of limit days (#3840)
 - [calendar] Fixed regression of calendarfetcherutils.shouldEventBeExcluded (#3841)
+- [core] Fixed socket.io timeout when server is slow to send notification, notification lost at client (#3380)
 
 ## [2.32.0] - 2025-07-01
 
diff --git a/js/server.js b/js/server.js
index 95fd2b82..3b4e2503 100644
--- a/js/server.js
+++ b/js/server.js
@@ -42,7 +42,9 @@ function Server (config) {
 					origin: /.*$/,
 					credentials: true
 				},
-				allowEIO3: true
+				allowEIO3: true,
+				pingInterval: 120000, // server → client ping every 2 mins
+				pingTimeout: 120000 // wait up to 2 mins for client pong
 			});
 
 			server.on("connection", (socket) => {
diff --git a/js/socketclient.js b/js/socketclient.js
index d8408e9e..73fdbf08 100644
--- a/js/socketclient.js
+++ b/js/socketclient.js
@@ -13,7 +13,9 @@ const MMSocket = function (moduleName) {
 		base = config.basePath;
 	}
 	this.socket = io(`/${this.moduleName}`, {
-		path: `${base}socket.io`
+		path: `${base}socket.io`,
+		pingInterval: 120000, // send pings every 2 mins
+		pingTimeout: 120000 // wait up to 2 mins for a pong
 	});
 
 	let notificationCallback = function () {};