diff --git a/common/include/prop/prop_array.h b/common/include/prop/prop_array.h
index 256208cbe78b..5d1361ac1de8 100644
--- a/common/include/prop/prop_array.h
+++ b/common/include/prop/prop_array.h
@@ -1,4 +1,4 @@
-/*     $NetBSD: prop_array.h,v 1.15 2017/01/29 00:16:19 christos Exp $    */
+/*     $NetBSD: prop_array.h,v 1.16 2017/01/29 02:07:44 christos Exp $    */
 
 /*-
  * Copyright (c) 2006, 2009 The NetBSD Foundation, Inc.
@@ -79,7 +79,8 @@ int		prop_array_recv_syscall(const struct plistref *,
 					prop_array_t *);
 #elif defined(_KERNEL)
 int		prop_array_copyin(const struct plistref *, prop_array_t *);
-int		prop_array_copyin_size(const struct plistref *, prop_array_t *);
+int		prop_array_copyin_size(const struct plistref *, prop_array_t *,
+				       size_t);
 int		prop_array_copyout(struct plistref *, prop_array_t);
 int		prop_array_copyin_ioctl(const struct plistref *, const u_long,
 					prop_array_t *);