diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 496f52e869..0225049192 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -685,11 +685,30 @@ bool AActor::TakeInventory(PClassActor *itemclass, int amount, bool fromdecorate
 
 void AActor::DestroyAllInventory ()
 {
-	while (Inventory != NULL)
+	AInventory *inv = Inventory;
+	if (inv != nullptr)
 	{
-		AInventory *item = Inventory;
-		item->Destroy ();
-		assert (item != Inventory);
+		TArray<AInventory *> toDelete;
+
+		// Delete the list in a two stage approach.
+		// This is necessary because an item may destroy another item (e.g. sister weapons)
+		// which would break the list and leave parts of it undestroyed, maybe doing bad things later.
+		while (inv != nullptr)
+		{
+			toDelete.Push(inv);
+			AInventory *item = inv->Inventory;
+			inv->Inventory = nullptr;
+			inv->Owner = nullptr;
+			inv = item;
+		}
+		for (auto p : toDelete)
+		{
+			// the item may already have been deleted by another one, so check this here to avoid problems.
+			if (!(p->ObjectFlags & OF_EuthanizeMe))
+			{
+				p->Destroy();
+			}
+		}
 	}
 }