diff --git a/process.c b/process.c
index cd6e59e290..9191051f99 100644
--- a/process.c
+++ b/process.c
@@ -7805,78 +7805,104 @@ InitVM_process(void)
     rb_define_module_function(rb_mProcess, "times", rb_proc_times, 0);
 
 #ifdef CLOCK_REALTIME
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_REALTIME", CLOCKID2NUM(CLOCK_REALTIME));
 #elif defined(RUBY_GETTIMEOFDAY_BASED_CLOCK_REALTIME)
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_REALTIME", RUBY_GETTIMEOFDAY_BASED_CLOCK_REALTIME);
 #endif
 #ifdef CLOCK_MONOTONIC
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC", CLOCKID2NUM(CLOCK_MONOTONIC));
 #elif defined(RUBY_MACH_ABSOLUTE_TIME_BASED_CLOCK_MONOTONIC)
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC", RUBY_MACH_ABSOLUTE_TIME_BASED_CLOCK_MONOTONIC);
 #endif
 #ifdef CLOCK_PROCESS_CPUTIME_ID
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_PROCESS_CPUTIME_ID", CLOCKID2NUM(CLOCK_PROCESS_CPUTIME_ID));
 #elif defined(RUBY_GETRUSAGE_BASED_CLOCK_PROCESS_CPUTIME_ID)
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_PROCESS_CPUTIME_ID", RUBY_GETRUSAGE_BASED_CLOCK_PROCESS_CPUTIME_ID);
 #endif
 #ifdef CLOCK_THREAD_CPUTIME_ID
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_THREAD_CPUTIME_ID", CLOCKID2NUM(CLOCK_THREAD_CPUTIME_ID));
 #endif
 #ifdef CLOCK_VIRTUAL
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_VIRTUAL", CLOCKID2NUM(CLOCK_VIRTUAL));
 #endif
 #ifdef CLOCK_PROF
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_PROF", CLOCKID2NUM(CLOCK_PROF));
 #endif
 #ifdef CLOCK_REALTIME_FAST
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_REALTIME_FAST", CLOCKID2NUM(CLOCK_REALTIME_FAST));
 #endif
 #ifdef CLOCK_REALTIME_PRECISE
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_REALTIME_PRECISE", CLOCKID2NUM(CLOCK_REALTIME_PRECISE));
 #endif
 #ifdef CLOCK_REALTIME_COARSE
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_REALTIME_COARSE", CLOCKID2NUM(CLOCK_REALTIME_COARSE));
 #endif
 #ifdef CLOCK_REALTIME_ALARM
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_REALTIME_ALARM", CLOCKID2NUM(CLOCK_REALTIME_ALARM));
 #endif
 #ifdef CLOCK_MONOTONIC_FAST
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC_FAST", CLOCKID2NUM(CLOCK_MONOTONIC_FAST));
 #endif
 #ifdef CLOCK_MONOTONIC_PRECISE
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC_PRECISE", CLOCKID2NUM(CLOCK_MONOTONIC_PRECISE));
 #endif
 #ifdef CLOCK_MONOTONIC_RAW
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC_RAW", CLOCKID2NUM(CLOCK_MONOTONIC_RAW));
 #endif
 #ifdef CLOCK_MONOTONIC_RAW_APPROX
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC_RAW_APPROX", CLOCKID2NUM(CLOCK_MONOTONIC_RAW_APPROX));
 #endif
 #ifdef CLOCK_MONOTONIC_COARSE
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_MONOTONIC_COARSE", CLOCKID2NUM(CLOCK_MONOTONIC_COARSE));
 #endif
 #ifdef CLOCK_BOOTTIME
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_BOOTTIME", CLOCKID2NUM(CLOCK_BOOTTIME));
 #endif
 #ifdef CLOCK_BOOTTIME_ALARM
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_BOOTTIME_ALARM", CLOCKID2NUM(CLOCK_BOOTTIME_ALARM));
 #endif
 #ifdef CLOCK_UPTIME
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_UPTIME", CLOCKID2NUM(CLOCK_UPTIME));
 #endif
 #ifdef CLOCK_UPTIME_FAST
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_UPTIME_FAST", CLOCKID2NUM(CLOCK_UPTIME_FAST));
 #endif
 #ifdef CLOCK_UPTIME_PRECISE
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_UPTIME_PRECISE", CLOCKID2NUM(CLOCK_UPTIME_PRECISE));
 #endif
 #ifdef CLOCK_UPTIME_RAW
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_UPTIME_RAW", CLOCKID2NUM(CLOCK_UPTIME_RAW));
 #endif
 #ifdef CLOCK_UPTIME_RAW_APPROX
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_UPTIME_RAW_APPROX", CLOCKID2NUM(CLOCK_UPTIME_RAW_APPROX));
 #endif
 #ifdef CLOCK_SECOND
+    /* see Process.clock_gettime */
     rb_define_const(rb_mProcess, "CLOCK_SECOND", CLOCKID2NUM(CLOCK_SECOND));
 #endif
     rb_define_module_function(rb_mProcess, "clock_gettime", rb_clock_gettime, -1);