diff --git a/src/main/java/de/thm/arsnova/services/UserService.java b/src/main/java/de/thm/arsnova/services/UserService.java
index 64c2dc322013af2efb64fc8339864a7e56530ea2..703b27cbfe880d93b91891c716dc11ec489617ab 100644
--- a/src/main/java/de/thm/arsnova/services/UserService.java
+++ b/src/main/java/de/thm/arsnova/services/UserService.java
@@ -55,7 +55,7 @@ public interface UserService extends EntityService<UserProfile> {
 
 	Set<UserAuthentication> getUsersByRoomShortId(String roomShortId);
 
-	String getRoomByUsername(String username);
+	String getRoomByUserId(String userId);
 
 	void addUserToRoomBySocketId(UUID socketId, String roomShortId);
 
diff --git a/src/main/java/de/thm/arsnova/services/UserServiceImpl.java b/src/main/java/de/thm/arsnova/services/UserServiceImpl.java
index e689e2ef9a3a33a7c75b56cb27b18b022446ba11..c6b2863321dae8751ac8ab2298471c6fe098309b 100644
--- a/src/main/java/de/thm/arsnova/services/UserServiceImpl.java
+++ b/src/main/java/de/thm/arsnova/services/UserServiceImpl.java
@@ -297,9 +297,9 @@ public class UserServiceImpl extends DefaultEntityServiceImpl<UserProfile> imple
 	}
 
 	@Override
-	public String getRoomByUsername(final String username) {
+	public String getRoomByUserId(final String userId) {
 		for (final Entry<UserAuthentication, String> entry  : userToRoomId.entrySet()) {
-			if (entry.getKey().getUsername().equals(username)) {
+			if (entry.getKey().getId().equals(userId)) {
 				return entry.getValue();
 			}
 		}
diff --git a/src/main/java/de/thm/arsnova/websocket/ArsnovaSocketioServerImpl.java b/src/main/java/de/thm/arsnova/websocket/ArsnovaSocketioServerImpl.java
index 51390f4001f944ee13e7f05d00015aa734c10916..121f1c0452fa915639e0859efc4eb2e36120bcc1 100644
--- a/src/main/java/de/thm/arsnova/websocket/ArsnovaSocketioServerImpl.java
+++ b/src/main/java/de/thm/arsnova/websocket/ArsnovaSocketioServerImpl.java
@@ -143,7 +143,7 @@ public class ArsnovaSocketioServerImpl implements ArsnovaSocketioServer, Arsnova
 
 					return;
 				}
-				final String roomShortId = userService.getRoomByUsername(u.getUsername());
+				final String roomShortId = userService.getRoomByUserId(u.getId());
 				final de.thm.arsnova.entities.Room room = roomService.getInternal(roomShortId, u);
 
 				if (room.getSettings().isFeedbackLocked()) {
@@ -167,7 +167,7 @@ public class ArsnovaSocketioServerImpl implements ArsnovaSocketioServer, Arsnova
 
 					return;
 				}
-				final String oldShortRoomId = userService.getRoomByUsername(u.getUsername());
+				final String oldShortRoomId = userService.getRoomByUserId(u.getId());
 				if (null != room.getKeyword() && room.getKeyword().equals(oldShortRoomId)) {
 					return;
 				}
@@ -254,8 +254,8 @@ public class ArsnovaSocketioServerImpl implements ArsnovaSocketioServer, Arsnova
 						) {
 					return;
 				}
-				final String username = userService.getUserToSocketId(client.getSessionId()).getUsername();
-				final String shortRoomId = userService.getRoomByUsername(username);
+				final String userId = userService.getUserToSocketId(client.getSessionId()).getId();
+				final String shortRoomId = userService.getRoomByUserId(userId);
 				userService.removeUserFromRoomBySocketId(client.getSessionId());
 				userService.removeUserToSocketId(client.getSessionId());
 				if (null != shortRoomId) {