diff --git a/sys/dev/usb/wlan/if_rsu.c b/sys/dev/usb/wlan/if_rsu.c
index e935dedcb77..ee650364b60 100644
--- a/sys/dev/usb/wlan/if_rsu.c
+++ b/sys/dev/usb/wlan/if_rsu.c
@@ -28,6 +28,8 @@ __FBSDID("$FreeBSD$");
  *   o power-save operation
  */
 
+#include "opt_wlan.h"
+
 #include <sys/param.h>
 #include <sys/endian.h>
 #include <sys/sockio.h>