diff --git a/sys/sys/mutex.h b/sys/sys/mutex.h
index ff17f6e39efa..eb38ffa28517 100644
--- a/sys/sys/mutex.h
+++ b/sys/sys/mutex.h
@@ -38,7 +38,6 @@
 #ifdef _KERNEL
 #include <sys/ktr.h>
 #include <machine/atomic.h>
-#include <machine/bus.h>
 #include <machine/cpufunc.h>
 #include <machine/globals.h>
 #endif	/* _KERNEL_ */