diff -Naru 1/vboxsf/utils.c 2/vboxsf/utils.c
--- 1/vboxsf/utils.c    2018-08-13 21:58:52.000000000 +0700
+++ 2/vboxsf/utils.c    2018-08-13 22:06:59.623300208 +0700
@@ -50,7 +50,11 @@
     RTTimeSpecSetNano(ts, t);
 }
 #else /* >= 2.6.0 */
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0))
 static void sf_ftime_from_timespec(struct timespec *tv, RTTIMESPEC *ts)
+#else
+static void sf_ftime_from_timespec(struct timespec64 *tv, RTTIMESPEC *ts)
+#endif //(LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0))
 {
     int64_t t = RTTimeSpecGetNano(ts);
     int64_t nsec;
@@ -60,7 +64,11 @@
     tv->tv_nsec = nsec;
 }

+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0))
 static void sf_timespec_from_ftime(RTTIMESPEC *ts, struct timespec *tv)
+#else
+static void sf_timespec_from_ftime(RTTIMESPEC *ts, struct timespec64 *tv)
+#endif //(LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0))
 {
     int64_t t = (int64_t)tv->tv_nsec + (int64_t)tv->tv_sec * 1000000000;
     RTTimeSpecSetNano(ts, t);