diff --git a/stable/presentation-time/presentation-time.xml b/stable/presentation-time/presentation-time.xml
index a10f703..c2431c5 100644
--- a/stable/presentation-time/presentation-time.xml
+++ b/stable/presentation-time/presentation-time.xml
@@ -25,7 +25,7 @@
     DEALINGS IN THE SOFTWARE.
   </copyright>
 
-  <interface name="wp_presentation" version="1">
+  <interface name="wp_presentation" version="2">
     <description summary="timed presentation related wl_surface requests">
 
 <!-- Introduction -->
@@ -123,7 +123,7 @@
 
   </interface>
 
-  <interface name="wp_presentation_feedback" version="1">
+  <interface name="wp_presentation_feedback" version="2">
     <description summary="presentation time feedback event">
       A presentation_feedback object returns an indication that a
       wl_surface content update has become visible to the user.
@@ -224,9 +224,12 @@
         targeting the next few vblanks. If such prediction cannot
         usefully be done, the argument is zero.
 
-        If the output does not have a constant refresh rate, explicit
-        video mode switches excluded, then the refresh argument must
-        be zero.
+        For version 2 and later, if the output does not have a constant
+        refresh rate, explicit video mode switches excluded, then the
+        refresh argument must be either an appropriate rate picked by the
+        compositor (e.g. fastest rate), or 0 if no such rate exists.
+        For version 1, if the output does not have a constant refresh rate,
+        the refresh argument must be zero.
 
         The 64-bit value combined from seq_hi and seq_lo is the value
         of the output's vertical retrace counter when the content