diff --git a/ChangeLog b/ChangeLog
index 0f66fc929c..68343d3c70 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Nov  3 14:42:55 2012  Kouhei Sutou  <kou@cozmixng.org>
+
+	* lib/rexml/output.rb (REXML::Output#initialize): Use normalized
+	  encoding name.
+
 Sat Nov  3 14:41:17 2012  Kouhei Sutou  <kou@cozmixng.org>
 
 	* lib/rexml/output.rb (REXML::Output): Don't output BOM in middle
diff --git a/lib/rexml/output.rb b/lib/rexml/output.rb
index 208bb0ade1..0c6cc7a7f8 100644
--- a/lib/rexml/output.rb
+++ b/lib/rexml/output.rb
@@ -10,7 +10,7 @@ module REXML
       @output = real_IO
       self.encoding = encd
 
-      @to_utf = encd != 'UTF-8'
+      @to_utf = encoding != 'UTF-8'
 
       if encoding == "UTF-16"
         @output << "\ufeff".encode("UTF-16BE")