diff --git a/sys/vm/vm_phys.c b/sys/vm/vm_phys.c
index 93fee70b2212..b47455d71b61 100644
--- a/sys/vm/vm_phys.c
+++ b/sys/vm/vm_phys.c
@@ -33,6 +33,7 @@
 __FBSDID("$FreeBSD$");
 
 #include "opt_ddb.h"
+#include "opt_vm.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>