diff --git a/chat-example/chat-vaadin-client/pom.xml b/chat-example/chat-vaadin-client/pom.xml
index 03e9732..57b06ff 100644
--- a/chat-example/chat-vaadin-client/pom.xml
+++ b/chat-example/chat-vaadin-client/pom.xml
@@ -51,7 +51,7 @@
     <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>javax.servlet-api</artifactId>
-      <version>3.0.1</version>
+      <version>4.0.1</version>
       <scope>provided</scope>
     </dependency>
     <dependency>