Add missing dependency
diff --git a/res/maven/tomcat-embed-websocket.pom b/res/maven/tomcat-embed-websocket.pom
index 464e2f0..a9f6070 100644
--- a/res/maven/tomcat-embed-websocket.pom
+++ b/res/maven/tomcat-embed-websocket.pom
@@ -34,6 +34,12 @@
   </licenses>
   <dependencies>
     <dependency>
+      <groupId>org.apache.tomcat</groupId>
+      <artifactId>tomcat-websocket-api</artifactId>
+      <version>@MAVEN.DEPLOY.VERSION@</version>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
       <groupId>org.apache.tomcat.embed</groupId>
       <artifactId>tomcat-embed-core</artifactId>
       <version>@MAVEN.DEPLOY.VERSION@</version>