diff --git a/ChangeLog b/ChangeLog
index 0751cc2eee..68270c3ba0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Feb 26 14:39:39 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* doc/extension.rdoc, doc/extension.ja.rdoc: add editor local
+	  variables, with commenting out by :enddoc: directives which are
+	  just ignored unless code object mode.  [Bug #12111]
+
 Fri Feb 26 12:25:56 2016  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
 
 	* doc/extension.ja.rdoc: removed rendering error caused by editor specific
diff --git a/doc/extension.ja.rdoc b/doc/extension.ja.rdoc
index 019bba3d8f..575b1ac742 100644
--- a/doc/extension.ja.rdoc
+++ b/doc/extension.ja.rdoc
@@ -1788,3 +1788,7 @@ rb_ary_store() などの，適切な API 関数を利用するようにして下
 
 そのほか，対応についての詳細は README.EXT の「Appendix D. Generational
 GC」を参照して下さい．
+
+:enddoc: Local variables:
+:enddoc: fill-column: 60
+:enddoc: end:
diff --git a/doc/extension.rdoc b/doc/extension.rdoc
index 48bb08661b..54612adae9 100644
--- a/doc/extension.rdoc
+++ b/doc/extension.rdoc
@@ -1821,3 +1821,7 @@ keyword in C.  RB_GC_GUARD has the following advantages:
    compilers and architectures. RB_GC_GUARD is customizable for broken
    systems/compilers without those without negatively affecting other
    systems.
+
+:enddoc: Local variables:
+:enddoc: fill-column: 70
+:enddoc: end: