diff --git a/ChangeLog b/ChangeLog
index 064154cffa..2657490689 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Thu Oct 25 13:09:01 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* parse.y: show a warning for concatenating string literals because
+	  it will be deprecated in the future.
+	  patched by mame (Yusuke Endoh) at [ruby-core:44207].
+	  [ruby-core:44156] [Feature #6265]
+
 Wed Oct 24 18:49:16 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/objspace/objspace.c (type2sym, count_objects_size): use enum
diff --git a/parse.y b/parse.y
index 7eaab6b1b8..7bf3149e2b 100644
--- a/parse.y
+++ b/parse.y
@@ -3810,6 +3810,7 @@ string		: tCHAR
 		| string string1
 		    {
 		    /*%%%*/
+			rb_warning0("string concatenation syntax will be deprecated");
 			$$ = literal_concat($1, $2);
 		    /*%
 			$$ = dispatch2(string_concat, $1, $2);