diff --git a/pbs-datastore/src/chunk_store.rs b/pbs-datastore/src/chunk_store.rs
index 75880331..1944ae00 100644
--- a/pbs-datastore/src/chunk_store.rs
+++ b/pbs-datastore/src/chunk_store.rs
@@ -215,10 +215,12 @@ impl ChunkStore {
         const UTIME_OMIT: i64 = (1 << 30) - 2;
 
         let times: [libc::timespec; 2] = [
+            // access time -> update to now
             libc::timespec {
                 tv_sec: 0,
                 tv_nsec: UTIME_NOW,
             },
+            // modification time -> keep as is
             libc::timespec {
                 tv_sec: 0,
                 tv_nsec: UTIME_OMIT,