diff --git a/ChangeLog b/ChangeLog
index 2a16a9222d..d60772d124 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Sep 20 11:43:08 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* lib/optparse.rb (summarize): separator "" should output new line.
+
 Sat Sep 20 08:07:34 2008  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* parse.y: strings which contain only US-ASCII don't force to have
diff --git a/lib/optparse.rb b/lib/optparse.rb
index aef3c0d486..f457b072a9 100644
--- a/lib/optparse.rb
+++ b/lib/optparse.rb
@@ -632,7 +632,7 @@ class OptionParser
       list.each do |opt|
         if opt.respond_to?(:summarize) # perhaps OptionParser::Switch
           opt.summarize(*args, &block)
-        elsif !opt
+        elsif !opt or opt.empty?
           yield("")
         elsif opt.respond_to?(:each_line)
           opt.each_line(&block)