diff --git a/ChangeLog b/ChangeLog
index 643c4ed309..5ba0d01d69 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jun 16 21:58:38 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/stringio/stringio.c (strio_each, strio_readlines): IO#each and
+	  IO#readlines do not affect $_.  [ruby-core:17277]
+
 Mon Jun 16 18:52:47 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/thwait.rb (ThreadsWait): Exception2MessageMapper no longer has
diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index d140ced7e7..b9c7eb7f80 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -953,7 +953,6 @@ strio_each(int argc, VALUE *argv, VALUE self)
     RETURN_ENUMERATOR(self, argc, argv);
 
     while (!NIL_P(line = strio_getline(argc, argv, readable(ptr)))) {
-	rb_lastline_set(line);
 	rb_yield(line);
     }
     return self;
@@ -975,7 +974,6 @@ strio_readlines(int argc, VALUE *argv, VALUE self)
     while (!NIL_P(line = strio_getline(argc, argv, readable(ptr)))) {
 	rb_ary_push(ary, line);
     }
-    rb_lastline_set(Qnil);
     return ary;
 }