diff --git a/general-info/release-20b.txt b/general-info/release-20b.txt
index 6c2008926de2878c34c7cc09ade3580db5975dea..3a4bc224850b688125ff4ff9b3abd77a963d8c51 100644
--- a/general-info/release-20b.txt
+++ b/general-info/release-20b.txt
@@ -58,6 +58,8 @@ New in this release:
       class object as well as a name.
     - Recognize but ignore the :DECLARE argument to
       ENSURE-GENERIC-FUNCTION. 
+    - Default documentation for short form of
+      DEFINE-METHOD-COMBINATION is NIL, not "".
 
   * Bugfixes:
     - On Unicode builds, printing of '|\|| and '|`| was incorrect
diff --git a/pcl/defcombin.lisp b/pcl/defcombin.lisp
index e45de6014ecdf7d47db00f9c5cbb9f755388f6d0..74f35c8a579c0aa55332d362ba603afb8cdd346e 100644
--- a/pcl/defcombin.lisp
+++ b/pcl/defcombin.lisp
@@ -25,7 +25,7 @@
 ;;; *************************************************************************
 
 (file-comment
-  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/pcl/defcombin.lisp,v 1.28 2010/03/19 15:19:03 rtoy Exp $")
+  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/pcl/defcombin.lisp,v 1.29 2010/04/17 20:12:25 rtoy Rel $")
 
 (in-package :pcl)
 (intl:textdomain "cmucl")
@@ -110,7 +110,7 @@
 (defun expand-short-defcombin (whole)
   (let* ((type (cadr whole))
 	 (documentation
-	   (getf (cddr whole) :documentation ""))
+	   (getf (cddr whole) :documentation nil))
 	 (identity-with-one-arg
 	   (getf (cddr whole) :identity-with-one-argument nil))
 	 (operator