diff --git a/lib/isc/rbtgen.c b/lib/isc/rbtgen.c
index f1d6efea99..ba5ef74afc 100644
--- a/lib/isc/rbtgen.c
+++ b/lib/isc/rbtgen.c
@@ -11,8 +11,6 @@
  *	MIT Press / McGraw Hill, 1990, ISBN 0-262-03141-8, chapter 14.
  */
 
-#include "attribute.h"
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>