diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 3ece6ce0fb8..92246d2f95c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2004-07-23  Matt Hodges  <matt@stchem.bham.ac.uk>  (tiny change)
+
+	* simple.el (completion-setup-function): Compute the common parts
+	and the first difference place correctly when
+	partial-completion-mode is on.
+
 2004-07-22  Vinicius Jose Latorre  <viniciusjl@ig.com.br>
 
 	* ps-print.el: Doc fix.  Improve the DSC compliance of the generated
diff --git a/lisp/simple.el b/lisp/simple.el
index 9d61a390575..1e112b1be74 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4313,6 +4313,13 @@ of the differing parts is, by contrast, slightly highlighted."
     (if minibuffer-completing-file-name
 	(with-current-buffer mainbuf
 	  (setq default-directory (file-name-directory mbuf-contents))))
+    ;; If partial-completion-mode is on, point might not be after the
+    ;; last character in the minibuffer.
+    ;; FIXME: This still doesn't work if the text to be completed
+    ;; starts with a `-'.
+    (when (and partial-completion-mode (not (eobp)))
+      (setq mbuf-contents
+	    (substring mbuf-contents 0 (- (point) (point-max)))))
     (with-current-buffer standard-output
       (completion-list-mode)
       (make-local-variable 'completion-reference-buffer)