diff --git a/ChangeLog b/ChangeLog
index cd35df87dd..e70174f6f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jul 21 13:36:54 2015  yuuji.yaginuma  <yuuji.yaginuma@gmail.com>
+
+	* lib/optparse.rb (complete): [DOC] fix typo.  [Fix GH-973]
+
 Tue Jul 21 05:20:21 2015  Eric Wong  <e@80x24.org>
 
 	* io.c (nogvl_wait_for_single_fd): new function for Linux
diff --git a/lib/optparse.rb b/lib/optparse.rb
index d5e367ea50..e2cd964351 100644
--- a/lib/optparse.rb
+++ b/lib/optparse.rb
@@ -1711,7 +1711,7 @@ XXX
   # Completes shortened long style option switch and returns pair of
   # canonical switch and switch descriptor OptionParser::Switch.
   #
-  # +id+::    Searching table.
+  # +typ+::   Searching table.
   # +opt+::   Searching key.
   # +icase+:: Search case insensitive if true.
   # +pat+::   Optional pattern for completion.