diff --git a/apps/openmw/mwworld/cellstore.cpp b/apps/openmw/mwworld/cellstore.cpp
index 99545a64f..59fa1f5e2 100644
--- a/apps/openmw/mwworld/cellstore.cpp
+++ b/apps/openmw/mwworld/cellstore.cpp
@@ -650,7 +650,8 @@ namespace MWWorld
             loadRef (ref, deleted, refNumToID);
         }
 
-        setLastRefNumIndex(refNumToID.rbegin()->first.mIndex);
+        if(refNumToID.size() != 0)
+            setLastRefNumIndex(refNumToID.rbegin()->first.mIndex);
 
         updateMergedRefs();
     }