diff --git a/lisp/ps-mule.el b/lisp/ps-mule.el
index a8b5210e965..ab8af40628a 100644
--- a/lisp/ps-mule.el
+++ b/lisp/ps-mule.el
@@ -673,7 +673,7 @@ the sequence."
 			(not (vectorp (aref (nth 2 composition) 0))))
 		   (car composition)
 		 to))
-	 (ascii-or-latin-1 "[\000-\377]+")
+	 (ascii-or-latin-1 "[\000-ÿ]+")
 	 (run-width 0)
 	 (endpos nil)
 	 (font-spec-table (aref ps-mule-font-spec-tables
@@ -699,6 +699,7 @@ the sequence."
 		 (setq composition (find-composition (point) to nil t))
 		 (setq stop (if composition (car composition) to)))))
 
+            ;; We fold lines that contain ASCII or Latin-1.
 	    ((looking-at ascii-or-latin-1)
 	     (let ((nchars (- (min (match-end 0) stop) (point))))
 	       (setq width (* average-width nchars))
@@ -710,6 +711,7 @@ the sequence."
 		 (setq run-width (+ run-width width))
 		 (forward-char nchars))))
 
+            ;; Don't fold other lines.  (But why?)
 	    (t
 	     (while (and (< (point) stop) (not endpos))
 	       (setq width (char-width (following-char)))