diff --git a/ChangeLog b/ChangeLog
index b9f851b060..9f4ac091b2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Nov 27 11:29:24 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/optparse.rb (OptionParser#candidate): get rid of 1.9 syntax
+	  so that BASERUBY can be 1.8.
+
 Sat Nov 27 08:16:21 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* addr2line.c (rb_dump_backtrace_with_lines): should close fd on
diff --git a/lib/optparse.rb b/lib/optparse.rb
index b21bd935c7..91308a9aef 100644
--- a/lib/optparse.rb
+++ b/lib/optparse.rb
@@ -1549,10 +1549,10 @@ XXX
     end
     pat = Completion.regexp(word, true)
     visit(:each_option) do |opt|
-      opts = [*(opt.long if long), *(opt.short if short)]
+      opts = (long ? opt.long : []) + (short ? opt.short [])
       opts = Completion.candidate(word, true, pat, &opts.method(:each)).map(&:first) if pat
       if /\A=/ =~ opt.arg
-        opts = opts.map {|sw| sw + "="}
+        opts.map! {|sw| sw + "="}
         if arg and CompletingHash === opt.pattern
           if opts = opt.pattern.candidate(arg, false, argpat)
             opts.map!(&:last)