diff --git a/sys/cddl/boot/zfs/lz4.c b/sys/cddl/boot/zfs/lz4.c
index c29f8614155d..b12122c765fc 100644
--- a/sys/cddl/boot/zfs/lz4.c
+++ b/sys/cddl/boot/zfs/lz4.c
@@ -34,6 +34,8 @@
  * $FreeBSD$
  */
 
+#include <arpa/inet.h>
+
 static int LZ4_uncompress_unknownOutputSize(const char *source, char *dest,
 					    int isize, int maxOutputSize);