diff --git a/ChangeLog b/ChangeLog
index 2e5e89cbba..4ebd0538b9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Dec 22 06:09:12 2007  David Flanagan  <david@davidflanagan.com>
+
+	* io.c: fix typo in rdoc comment
+
 Sat Dec 22 05:09:43 2007  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* parse.y (parser_str_new, rb_intern3): rb_default_encoding() renamed.
diff --git a/io.c b/io.c
index 567e7b5d5d..5cd7f7c14d 100644
--- a/io.c
+++ b/io.c
@@ -5686,7 +5686,7 @@ rb_io_s_read(int argc, VALUE *argv, VALUE io)
 
 /*
  *  call-seq:
- *     io.externalencoding   => encoding
+ *     io.external_encoding   => encoding
  *
  *  Returns the Encoding object that represents the encoding of the file.
  */