Spring boot adapter can't logout under Jetty

Securing applications
1

Using Spring boot keycloak adapter with Jetty servlet container generates exception on /k_logout:

2020-03-10 10:37:24,864 [app] WARN  org.eclipse.jetty.server.HttpChannel - /k_logout
java.lang.IllegalAccessError: class org.keycloak.adapters.jetty.Jetty94SessionManager tried to access protected method 'javax.servlet.http.HttpSession org.eclipse.jetty.server.session.SessionHandler.getHttpSession(java.lang.String)' (org.keycloak.adapters.jetty.Jetty94SessionManager and org.eclipse.jetty.server.session.SessionHandler are in unnamed module of loader org.springframework.boot.loader.LaunchedURLClassLoader @45ff54e6)
at org.keycloak.adapters.jetty.Jetty94SessionManager.getHttpSession(Jetty94SessionManager.java:38)

Under Tomcat and Undertow it works correctly.