Index: /trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.c
===================================================================
--- /trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.c	(revision 39787)
+++ /trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.c	(revision 39788)
@@ -415,4 +415,5 @@
 static int sf_remount_fs(struct super_block *sb, int *flags, char *data)
 {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 23)
     struct sf_glob_info *sf_g;
     struct vbsf_mount_info_new *info;
@@ -452,4 +453,7 @@
     printk(KERN_DEBUG "LEAVE: sf_remount_fs\n");
     return 0;
+#else
+    return -ENOSYS;
+#endif
 }