diff --git a/process.c b/process.c
index fbb737d9bd..b02fa59e42 100644
--- a/process.c
+++ b/process.c
@@ -7652,6 +7652,7 @@ ruby_real_ms_time(void)
  *  [CLOCK_UPTIME_RAW_APPROX] macOS 10.12
  *  [CLOCK_UPTIME_PRECISE] FreeBSD 8.1
  *  [CLOCK_SECOND] FreeBSD 8.1
+ *  [CLOCK_TAI] Linux 3.10
  *
  *  Note that SUS stands for Single Unix Specification.
  *  SUS contains POSIX and clock_gettime is defined in the POSIX part.
@@ -8407,6 +8408,10 @@ InitVM_process(void)
 #ifdef CLOCK_SECOND
     /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_SECOND", CLOCKID2NUM(CLOCK_SECOND));
+#endif
+#ifdef CLOCK_TAI
+    /* see Process.clock_gettime */
+    rb_define_const(rb_mProcess, "CLOCK_TAI", CLOCKID2NUM(CLOCK_TAI));
 #endif
     rb_define_module_function(rb_mProcess, "clock_gettime", rb_clock_gettime, -1);
     rb_define_module_function(rb_mProcess, "clock_getres", rb_clock_getres, -1);