diff --git a/src/de/steamwar/schematicsystem/check/CheckSession.java b/src/de/steamwar/schematicsystem/check/CheckSession.java
index 8cfa079..8c7f8e6 100644
--- a/src/de/steamwar/schematicsystem/check/CheckSession.java
+++ b/src/de/steamwar/schematicsystem/check/CheckSession.java
@@ -43,6 +43,8 @@ public class CheckSession {
     }
 
     public static CheckSession getCheckSession() {
+        if(checkSessions.isEmpty())
+            return null;
         return checkSessions.iterator().next();
     }