diff --git a/ChangeLog b/ChangeLog
index 2657490689..9a30a25cca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Oct 25 13:35:07 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* tool/mkconfig.rb: remove string literal concatenation.
+
 Thu Oct 25 13:09:01 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* parse.y: show a warning for concatenating string literals because
diff --git a/tool/mkconfig.rb b/tool/mkconfig.rb
index 7e943f3c21..e5203c4d2a 100755
--- a/tool/mkconfig.rb
+++ b/tool/mkconfig.rb
@@ -128,7 +128,7 @@ File.foreach "config.status" do |line|
         val.sub!(/universal/, %q[#{arch && universal[/(?:\A|\s)#{Regexp.quote(arch)}=(\S+)/, 1] || '\&'}])
       end
     end
-    v = "  CONFIG[\"#{name}\"] #{win32 && vars[name] ? '<< "\n"' : '='} #{val}\n"
+    v = "  CONFIG[\"#{name}\"] #{win32 && vars[name] ? '<< "\n" +' : '='} #{val}\n"
     vars[name] = true
     if fast[name]
       v_fast << v