Index: head/sys/kern/vfs_export.c
===================================================================
--- head/sys/kern/vfs_export.c
+++ head/sys/kern/vfs_export.c
@@ -61,6 +61,9 @@
 #include <netinet/in.h>
 #include <net/radix.h>
 
+#include <rpc/types.h>
+#include <rpc/auth.h>
+
 static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure");
 
 #if defined(INET) || defined(INET6)
@@ -303,7 +306,7 @@
 		return (EINVAL);
 
 	if ((argp->ex_flags & MNT_EXPORTED) != 0 &&
-	    (argp->ex_numsecflavors <= 0
+	    (argp->ex_numsecflavors < 0
 	    || argp->ex_numsecflavors >= MAXSECFLAVORS))
 		return (EINVAL);
 
@@ -340,6 +343,10 @@
 			MNT_ILOCK(mp);
 			mp->mnt_flag |= MNT_EXPUBLIC;
 			MNT_IUNLOCK(mp);
+		}
+		if (argp->ex_numsecflavors == 0) {
+			argp->ex_numsecflavors = 1;
+			argp->ex_secflavors[0] = AUTH_SYS;
 		}
 		if ((error = vfs_hang_addrlist(mp, nep, argp)))
 			goto out;
Index: head/sys/kern/vfs_mount.c
===================================================================
--- head/sys/kern/vfs_mount.c
+++ head/sys/kern/vfs_mount.c
@@ -70,9 +70,6 @@
 
 #include <machine/stdarg.h>
 
-#include <rpc/types.h>
-#include <rpc/auth.h>
-
 #include <security/audit/audit.h>
 #include <security/mac/mac_framework.h>
 
@@ -1131,8 +1128,6 @@
 		switch (len) {
 		case (sizeof(struct oexport_args)):
 			bzero(&o2export, sizeof(o2export));
-			o2export.ex_numsecflavors = 1;
-			o2export.ex_secflavors[0] = AUTH_SYS;
 			/* FALLTHROUGH */
 		case (sizeof(o2export)):
 			bcopy(bufp, &o2export, len);