diff --git a/etc/NEWS b/etc/NEWS
index fdbfd9b1bea..3fdb6212156 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -287,12 +287,13 @@ height use 'window-height' in combination with 'body-lines'.
 
 +++
 *** Deleted frames can now be undeleted.
-The most recently deleted frame can be undeleted with 'C-x 5 u' when
-the new user option 'undelete-frame-max' has its default value 1.
-Without a prefix argument, undelete the most recently deleted frame.
-With a numerical prefix argument between 1 and 'undelete-frame-max',
-where 1 is the most recently deleted frame, undelete the corresponding
-deleted frame.
+The most recently deleted frame can be undeleted with 'C-x 5 u'
+if the new user option 'undelete-frame-max' is a positive number.
+This option specifies the maximum number of closed frames to remember.
+The default is 1.  Without a prefix argument, undelete the most
+recently deleted frame.  With a numerical prefix argument between 1
+and the value of 'undelete-frame-max', where 1 is the most recently
+deleted frame, undelete the corresponding deleted frame.
 
 ** Tab Bars and Tab Lines