diff --git a/CodeWalker.Core/GameFiles/MetaTypes/Archetype.cs b/CodeWalker.Core/GameFiles/MetaTypes/Archetype.cs
index f5fa40836..a7ea57d3e 100644
--- a/CodeWalker.Core/GameFiles/MetaTypes/Archetype.cs
+++ b/CodeWalker.Core/GameFiles/MetaTypes/Archetype.cs
@@ -380,6 +380,8 @@ public void RemoveEntitySet(MCMloEntitySet set)
 
         private void FixPortalIndexes(int deletedIndex)
         {
+            if (portals == null) return;
+
             foreach (var portal in portals)
             {
                 List<uint> newAttachedObjects = new List<uint>();