diff --git a/sys/dev/bktr/bktr_os.c b/sys/dev/bktr/bktr_os.c
index 7db3f83a805f..5697f462777d 100644
--- a/sys/dev/bktr/bktr_os.c
+++ b/sys/dev/bktr/bktr_os.c
@@ -50,6 +50,7 @@
 
 #ifdef __FreeBSD__
 #include "bktr.h"
+#include "smbus.h"
 #endif /* __FreeBSD__ */
 
 #include "opt_bktr.h"		/* include any kernel config options */