diff --git a/lisp/mouse.el b/lisp/mouse.el
index 21264adf6ad..1e9b664c36e 100644
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -1204,7 +1204,8 @@ and selects that window."
 	  (if (null beg)
 	      (error "No completion here"))
 	  (setq beg (previous-single-property-change beg 'mouse-face))
-	  (setq end (next-single-property-change end 'mouse-face))
+	  (setq end (or (next-single-property-change end 'mouse-face)
+			(point-max)))
 	  (setq choice (buffer-substring beg end)))))
     (let ((owindow (selected-window)))
       (select-window (posn-window (event-start event)))