diff --git a/ChangeLog b/ChangeLog
index 8e37938670..3ba7cd6ec9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jun  3 01:34:59 2014  Zachary Scott  <e@zzak.io>
+
+	* README.EXT: [DOC] Add rb_call_super when subclassing from @robin850
+	  [Fixes GH-623] https://github.com/ruby/ruby/pull/623
+
 Mon Jun  2 17:14:49 2014  Koichi Sasada  <ko1@atdot.net>
 
 	* vm.c (ruby_vm_destruct): remove useless call of
diff --git a/README.EXT b/README.EXT
index d66d6c5576..756f46f98b 100644
--- a/README.EXT
+++ b/README.EXT
@@ -412,6 +412,11 @@ func has to take the klass as the argument and return a newly
 allocated instance.  This instance should be as empty as possible,
 without any expensive (including external) resources.
 
+If you are overriding an existing method of any ancestor of your class,
+you may rely on:
+
+  VALUE rb_call_super(int argc, const VALUE *argv)
+
 === Constant Definition
 
 We have 2 functions to define constants: