diff --git a/src/nat/Archive.kiss b/src/nat/Archive.kiss
index 766f833..8326b50 100644
--- a/src/nat/Archive.kiss
+++ b/src/nat/Archive.kiss
@@ -29,8 +29,10 @@
         (refreshEntry e)
         e))
 
-// After modifying an entry, this must be called. If you are writing in a createEntry initializer or a system's processEntry function, this will happen automatically.
-// Otherwise, you can guarantee it happens automatically by using the (withWritableEntry) macro in Lib.kiss
+// After modifying an entry, this must be called. If you are writing in a createEntry
+// initializer or a system's processEntry function, this will happen automatically.
+// Otherwise, you can guarantee it happens automatically by using the (withWritableEntry)
+// and (withWritableComponents) macros in Lib.kiss
 (method refreshEntry [:Entry e]
     (_saveEntry e)
     (doFor system systems
diff --git a/src/nat/System.kiss b/src/nat/System.kiss
index 7f2bd3a..3577251 100644
--- a/src/nat/System.kiss
+++ b/src/nat/System.kiss
@@ -9,9 +9,13 @@
             &prop :EntryProcessor processEntry]
     [])
 
+(prop &mut :Null<EntryProcessor> onRemoveEntry)
+
 (method :Void checkEntryInOrOut [:Archive archive :Entry e]
     (if (canProcessEntry archive e)
             (dictSet entries e.id e)
-        (entries.remove e.id)))
+        (when (entries.exists e.id)
+            (entries.remove e.id)
+            (when onRemoveEntry (onRemoveEntry archive e)))))
 
 // TODO systems may need access to a UI