--- a/Smalltalk.st	Fri Nov 18 14:57:52 2016 +0100
+++ b/Smalltalk.st	Fri Nov 18 16:03:33 2016 +0100
@@ -2189,6 +2189,7 @@
 !
 
 allKeysDo:aBlock
+    <resource: #obsolete>
     "evaluate the argument, aBlock for all keys in the Smalltalk dictionary"
 
     self keysDo:aBlock