diff --git a/sys/dev/aac/aac_debug.c b/sys/dev/aac/aac_debug.c
index a72f9c9f9d5..5f02391e553 100644
--- a/sys/dev/aac/aac_debug.c
+++ b/sys/dev/aac/aac_debug.c
@@ -37,6 +37,7 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
+#include <sys/conf.h>
 
 #include <dev/aac/aac_compat.h>
 #include <sys/bus.h>