Index: head/sys/kern/vfs_mount.c
===================================================================
--- head/sys/kern/vfs_mount.c
+++ head/sys/kern/vfs_mount.c
@@ -2343,10 +2343,22 @@
 	return (error);
 }
 
+/*
+ * Convert the old export args format into new export args.
+ *
+ * The old export args struct does not have security flavors.  Otherwise, the
+ * structs are identical.  The default security flavor 'sys' is applied when
+ * the given args export the filesystem.
+ */
 void
 vfs_oexport_conv(const struct oexport_args *oexp, struct export_args *exp)
 {
 
 	bcopy(oexp, exp, sizeof(*oexp));
-	exp->ex_numsecflavors = 0;
+	if (exp->ex_flags & MNT_EXPORTED) {
+		exp->ex_numsecflavors = 1;
+		exp->ex_secflavors[0] = AUTH_SYS;
+	} else {
+		exp->ex_numsecflavors = 0;
+	}
 }