diff --git a/sys/net/pfvar.h b/sys/net/pfvar.h
index f4c503d844c0..824b8ec3f488 100644
--- a/sys/net/pfvar.h
+++ b/sys/net/pfvar.h
@@ -41,6 +41,7 @@
 #include <sys/cpuset.h>
 #include <sys/malloc.h>
 #include <sys/refcount.h>
+#include <sys/lock.h>
 #include <sys/rmlock.h>
 #include <sys/tree.h>
 #include <vm/uma.h>