diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index cbae73edfd0..9cd895c4f35 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2009-03-20  Dan Nicolaescu  <dann@ics.uci.edu>
+
+	* vc-dir.el (vc-dir-deduce-fileset): Make the error message more explicit.
+
 2009-03-19  Juanma Barranquero  <lekktu@gmail.com>
 
 	* subr.el (forward-point): Add obsolescence declaration.
diff --git a/lisp/vc-dir.el b/lisp/vc-dir.el
index d2414f9172f..4ac5ed6852a 100644
--- a/lisp/vc-dir.el
+++ b/lisp/vc-dir.el
@@ -1101,7 +1101,7 @@ outside of VC) and one wants to do some operation on it."
       ;; state to decide which operation to perform.
       (dolist (crt (cdr only-files-list))
 	(unless (vc-compatible-state (cdr crt) state)
-	  (error "%s:%s clashes with %s:%s"
+	  (error "When applying VC operations to multiple files, the files are required\nto  be in similar VC states.\n%s in state %s clashes with %s in state %s"
 		 (car crt) (cdr crt) (caar only-files-list) state)))
       (setq only-files-list (mapcar 'car only-files-list))
       (when (and state (not (eq state 'unregistered)))