diff --git a/doc/publican/sources/Protocol.xml b/doc/publican/sources/Protocol.xml
index 89d76d8e..9aa2ca16 100644
--- a/doc/publican/sources/Protocol.xml
+++ b/doc/publican/sources/Protocol.xml
@@ -368,8 +368,8 @@
       trigger further requests (such as button presses, key events,
       pointer motions) carry serial numbers, and requests such as
       wl_surface.set_popup require that the serial number of the
-      triggering event is specified. The server maintains a
-      monotonically increasing counter for these serial numbers.
+      triggering event is specified. Serial numbers are opaque,
+      clients should not assign any meaning to them.
     </para>
     <para>
       Input events also carry timestamps with millisecond granularity.
diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index d1a75a7d..262cf8f2 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -46,7 +46,7 @@
 	compositor after the callback is fired and as such the client must not
 	attempt to use it after that point.
 
-	The callback_data passed in the callback is the event serial.
+	The callback_data passed in the callback is not specified.
       </description>
       <arg name="callback" type="new_id" interface="wl_callback"
 	   summary="callback object for the sync request"/>