diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc
index 21d632e83a..fa56e880b3 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -1691,10 +1691,23 @@ one pending bit to be allocated.
 Defaults to 20 bits (to cover at most 1048576 interrupts).
 
 ### mce (x86)
-> `= <integer>`
+> `= <boolean>`
+
+> Default: `true`
+
+Allows to disable the use of Machine Check Exceptions.  Note that doing
+so may result in silent shutdown of the system in case an event occurs
+which would have resulted in raising a Machine Check Exception.  Silent
+here is as far as Xen is concerned; firmware may offer to retrieve some
+collected data.
 
 ### mce_fb (Intel)
-> `= <integer>`
+> `= <boolean>`
+
+> Default: `false`
+
+Force broadcasting of Machine Check Exceptions, suppressing the use of
+Local MCE functionality available in newer Intel hardware.
 
 ### mce_verbosity (x86)
 > `= verbose`