diff --git a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
index c2687b09bba6e557891012f80f5053cee628b4a7..a3f692b3d696550955a68f9f07fb4c45269d1208 100644
--- a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
+++ b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
@@ -892,6 +892,7 @@ public class CouchDBDao implements IDatabaseDao {
 
 	@Override
 	public final int countActiveUsers(Session session, long since) {
+		if (session == null) throw new NotFoundException();
 		try {
 			View view = new View("logged_in/count");
 			view.setStartKey(