diff --git a/ChangeLog b/ChangeLog
index 78f3796797..62fbae0afb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Mar 17 16:25:53 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* hash.c (rb_hash_aset): allow recursive key.  [ruby-core:24648]
+
 Wed Mar 17 06:39:59 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.h (rb_warning, rb_sys_warning): fixed typo in rdoc.
diff --git a/hash.c b/hash.c
index dda685012c..0b863bd637 100644
--- a/hash.c
+++ b/hash.c
@@ -1096,9 +1096,6 @@ rb_hash_aset(VALUE hash, VALUE key, VALUE val)
 {
     rb_hash_modify(hash);
     hash_update(hash, key);
-    if (hash == key) {
-	rb_raise(rb_eArgError, "recursive key for hash");
-    }
     if (RHASH(hash)->ntbl->type == &identhash || rb_obj_class(key) != rb_cString) {
 	st_insert(RHASH(hash)->ntbl, key, val);
     }