diff --git a/sys/dev/hwt/hwt_contexthash.c b/sys/dev/hwt/hwt_contexthash.c
index c73415e03fb..5682b7d38e5 100644
--- a/sys/dev/hwt/hwt_contexthash.c
+++ b/sys/dev/hwt/hwt_contexthash.c
@@ -30,6 +30,7 @@
 
 #include <sys/param.h>
 #include <sys/kernel.h>
+#include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mutex.h>
 #include <sys/refcount.h>