diff --git a/ChangeLog b/ChangeLog
index 8e4b50a20d..8ef0432657 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Nov  6 14:25:09 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* lib/net/protocol.rb (Net::InternetMessageIO#each_crlf_line):
+	  don't use /n in universal regexp. [ruby-dev:46394] [Bug #7278]
+
 Tue Nov  6 09:42:26 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* string.c (rb_str_b): Add String#b, returning a copied string
diff --git a/lib/net/protocol.rb b/lib/net/protocol.rb
index 9733d56c93..6b79f9efcc 100644
--- a/lib/net/protocol.rb
+++ b/lib/net/protocol.rb
@@ -322,7 +322,7 @@ module Net # :nodoc:
 
     def each_crlf_line(src)
       buffer_filling(@wbuf, src) do
-        while line = @wbuf.slice!(/\A.*(?:\n|\r\n|\r(?!\z))/n)
+        while line = @wbuf.slice!(/\A.*(?:\n|\r\n|\r(?!\z))/)
           yield line.chomp("\n") + "\r\n"
         end
       end
diff --git a/test/net/protocol/test_protocol.rb b/test/net/protocol/test_protocol.rb
new file mode 100644
index 0000000000..5fe3023015
--- /dev/null
+++ b/test/net/protocol/test_protocol.rb
@@ -0,0 +1,11 @@
+require "test/unit"
+require "net/protocol"
+require "stringio"
+
+class TestProtocol < Test::Unit::TestCase
+  def test_each_crlf_line
+    assert_output('', '') do
+      Net::InternetMessageIO.new(StringIO.new("")).write_message("\u3042\r\n\u3044\r\n\u3046")
+    end
+  end
+end