diff --git a/ChangeLog b/ChangeLog
index 62550f8cfb..50be3068bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -8,6 +8,9 @@ Sat Jun 17 09:03:47 2006  Kouhei Sutou  <kou@cozmixng.org>
 	* lib/rss/trackback.rb: added TrackBack prefix.
 	* lib/rss/maker/trackback.rb: ditto.
 
+	* lib/rss/rss.rb : removed needless argument 'prefix'.
+	* lib/rss/parser.rb: ditto.
+
 Sat Jun 17 02:01:00 2006  Tanaka Akira  <akr@m17n.org>
 
 	* lib/pp.rb (Kernel#pretty_inspect): defined for pretty printed
diff --git a/lib/rss/parser.rb b/lib/rss/parser.rb
index 6b3fe06419..3904feb759 100644
--- a/lib/rss/parser.rb
+++ b/lib/rss/parser.rb
@@ -407,9 +407,7 @@ module RSS
       previous = @last_element
       next_element = klass.send(:new, *args)
       next_element.do_validate = @do_validate
-      prefix = ""
-      prefix << "#{klass.required_prefix}_" if klass.required_prefix
-      previous.instance_eval {set_next_element(prefix, tag_name, next_element)}
+      previous.instance_eval {set_next_element(tag_name, next_element)}
       @last_element = next_element
       @proc_stack.push Proc.new { |text, tags|
         p(@last_element.class) if DEBUG
diff --git a/lib/rss/rss.rb b/lib/rss/rss.rb
index fc0cd7b1c6..d2b7604488 100644
--- a/lib/rss/rss.rb
+++ b/lib/rss/rss.rb
@@ -665,7 +665,7 @@ EOC
       end
     end
 
-    def set_next_element(prefix, tag_name, next_element)
+    def set_next_element(tag_name, next_element)
       klass = next_element.class
       prefix = ""
       prefix << "#{klass.required_prefix}_" if klass.required_prefix