diff --git a/lib/internal/process.js b/lib/internal/process.js
index 0f514a50e31745..5334d8c58bc0a2 100644
--- a/lib/internal/process.js
+++ b/lib/internal/process.js
@@ -74,7 +74,9 @@ function setup_cpuUsage() {
   };
 }
 
-
+// The 3 entries filled in by the original process.hrtime contains
+// the upper/lower 32 bits of the second part of the value,
+// and the remaining nanoseconds of the value.
 function setup_hrtime() {
   const _hrtime = process.hrtime;
   const hrValues = new Uint32Array(3);