diff --git a/README.md b/README.md
index 67880ef..bff071d 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,7 @@ A few environment variables allow you to customize the behavior of the sync:
 * `CRON_ABORT` crontab schedule `0 6 * * *` to abort sync at 6am
 * `FORCE_SYNC` set variable to perform a sync upon boot
 * `CHECK_URL` [healthchecks.io](https://healthchecks.io) url or similar cron monitoring to perform a `GET` after a successful sync
+* `START_URL` same as `CHECK_URL`, but is called before sync starts. If `CHECK_URL` is defined as a healthchecks.io URL, this defaults to [${CHECK_URL}/start](https://healthchecks.io/docs/#start-event).
 * `SYNC_OPTS` additional options for `rclone sync` command. Defaults to `-v`
 * `TZ` set the [timezone](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) to use for the cron and log `America/Argentina/Buenos_Aires`
 
diff --git a/sync.sh b/sync.sh
index 937235f..7e262d7 100755
--- a/sync.sh
+++ b/sync.sh
@@ -12,11 +12,23 @@ else
 echo $$ > /tmp/sync.pid
 
 if test "$(rclone ls --max-depth 1 $SYNC_SRC $RCLONE_OPTS)"; then
+  # Send a start ping if a) START_URL is explicitly set OR b) if Healthchecks.io is used as CHECK_URL provider
+  if [ -z ${START_URL+x} ]
+  then
+    if echo "$CHECK_URL" | grep "hc-ping"
+    then
+      wget "$CHECK_URL/start" -O /dev/null
+    fi
+  else
+    wget $START_URL -O /dev/null
+  fi
+    
   # the source directory is not empty
   # it can be synced without clear data loss
   echo "INFO: Starting rclone sync $SYNC_SRC $SYNC_DEST $RCLONE_OPTS $SYNC_OPTS"
   rclone sync $SYNC_SRC $SYNC_DEST $RCLONE_OPTS $SYNC_OPTS
 
+  # Send "done" ping to HC, if set
   if [ -z "$CHECK_URL" ]
   then
     echo "INFO: Define CHECK_URL with https://healthchecks.io to monitor sync job"