diff --git a/ChangeLog b/ChangeLog
index 310e47dace..5eb77c9870 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Sep 23 08:25:56 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* hash.c (env_aset): allow nil value to remove an entry.
+	  [ruby-dev:36465]
+
 Tue Sep 23 08:07:07 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* misc/ruby-mode.el (ruby-keyword-end-re): emacs21 support.  a
diff --git a/hash.c b/hash.c
index 694b619529..bc627d868f 100644
--- a/hash.c
+++ b/hash.c
@@ -2052,7 +2052,8 @@ env_aset(VALUE obj, VALUE nm, VALUE val)
     }
 
     if (NIL_P(val)) {
-	rb_raise(rb_eTypeError, "cannot assign nil; use Hash#delete instead");
+	env_delete(obj, nm);
+	return Qnil;
     }
     StringValue(nm);
     StringValue(val);