diff --git a/dix/getevents.c b/dix/getevents.c
index 2f6153736..652bd6758 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -201,10 +201,10 @@ CreateClassesChangedEvent(EventList* event,
     dce->time = ms;
     if (master->u.lastSlave)
     {
-        dce->flags |= HAS_OLD_SLAVE;
+        dce->flags |= DEVCHANGE_HAS_OLD_SLAVE;
         dce->old_slaveid = master->u.lastSlave->id;
     }
-    dce->flags |= HAS_NEW_SLAVE;
+    dce->flags |= DEVCHANGE_HAS_NEW_SLAVE;
     dce->new_slaveid = slave->id;
 
     if (slave->button)
diff --git a/include/events.h b/include/events.h
index 6803b5b7b..871932049 100644
--- a/include/events.h
+++ b/include/events.h
@@ -112,9 +112,9 @@ typedef struct
 } DeviceEvent;
 
 
-/* Flags used in DeviceChangedEvent to signal if new/old slave is present */
-#define HAS_OLD_SLAVE 0x1
-#define HAS_NEW_SLAVE 0x2
+/* Flags used in DeviceChangedEvent to signal if new/old slave is present. */
+#define DEVCHANGE_HAS_OLD_SLAVE 0x1
+#define DEVCHANGE_HAS_NEW_SLAVE 0x2
 
 /**
  * Sent whenever a device's capabilities have changed.