--- a/ImmutableArray.st	Tue Oct 04 12:23:43 2016 +0200
+++ b/ImmutableArray.st	Tue Oct 04 12:23:58 2016 +0200
@@ -127,6 +127,12 @@
     "return a writable copy of myself"
 
     ^ self copy changeClassTo:Array
+!
+
+beImmutable
+    "that's what I am"
+
+    ^ self
 ! !
 
 !ImmutableArray methodsFor:'copying'!