diff --git a/asdf.lisp b/asdf.lisp
index 946e7c48ded70d5900b72b918683e6b9fdbc5ceb..99875e8e4a60069690b82c2ef9656e168c9a23b7 100644
--- a/asdf.lisp
+++ b/asdf.lisp
@@ -251,7 +251,7 @@
   ;; This parameter isn't actually user-visible
   ;; -- please use the exported function ASDF:ASDF-VERSION below.
   ;; the 1+ hair is to ensure that we don't do an inadvertent find and replace
-  (subseq "VERSION:1.640" (1+ (length "VERSION"))))
+  (subseq "VERSION:1.641" (1+ (length "VERSION"))))
 
 (defun asdf-version ()
   "Exported interface to the version of ASDF currently installed. A string.