diff --git a/proto/protocol.xml b/proto/protocol.xml
index bf77176..9a3306d 100644
--- a/proto/protocol.xml
+++ b/proto/protocol.xml
@@ -1747,7 +1747,7 @@
         It is a protocol violation to send requests or events for unbound
         capabilities.
       </description>
-      <arg name="capabilities" type="uint32" enum="capability" summary="A mask of capabilities that the client wishes to handle"/>
+      <arg name="capabilities" type="uint32" summary="A mask of 'capability' flags that the client wishes to handle"/>
     </request>
 
     <request name="proximity_in" since="1" context-type="sender">
@@ -2037,7 +2037,7 @@
         ei_stylus.bind_tool_capabilities request before the device will
         send events.
       </description>
-      <arg name="capabilities" type="uint32" enum="capability" summary="A capability mask for the events available through this interface"/>
+      <arg name="capabilities" type="uint32" summary="A mask of 'capability' flags for the events available through this interface"/>
     </event>
 
     <event name="proximity_in" since="1" context-type="receiver">