diff --git a/src/main/java/de/thm/arsnova/services/SessionService.java b/src/main/java/de/thm/arsnova/services/SessionService.java
index 0d63d14a80ef35230a96756db568389880948199..07747a1c248d63fe2e220dc907df848c2091a4b7 100644
--- a/src/main/java/de/thm/arsnova/services/SessionService.java
+++ b/src/main/java/de/thm/arsnova/services/SessionService.java
@@ -67,7 +67,9 @@ public class SessionService implements ISessionService {
 
 		Session session = databaseDao.getSession(keyword);
 		if (null == session) {
-			throw new NotFoundException();
+			userService.removeUserFromSessionBySocketId(socketId);
+
+			return null;
 		}
 		User user = userService.getUser2SocketId(socketId);