diff --git a/README.md b/README.md
index 144ebdf..8d51436 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ pg_backup_s3:
     POSTGRES_PASSWORD: password
 ```
 - Images are tagged by the major PostgreSQL version they support: `9`, `10`, `11`, `12`, or `13`.
-- The `SCHEDULE` variable determines backup frequency. See go-cron schedules documentation [here](http://godoc.org/github.com/robfig/cron#hdr-Predefined_schedules).
+- The `SCHEDULE` variable determines backup frequency. See go-cron schedules documentation [here](http://godoc.org/github.com/robfig/cron#hdr-Predefined_schedules). Omit to run the backup immediately and then exit.
 - If `PASSPHRASE` is provided, the backup will be encrypted using GPG.
 - Run `docker exec <container name> sh backup.sh` to trigger a backup ad-hoc
 
diff --git a/src/run.sh b/src/run.sh
index 1571598..90b5fcb 100644
--- a/src/run.sh
+++ b/src/run.sh
@@ -3,13 +3,11 @@
 set -eu
 
 if [ "$S3_S3V4" = "yes" ]; then
-    aws configure set default.s3.signature_version s3v4
+  aws configure set default.s3.signature_version s3v4
 fi
 
 if [ -z "$SCHEDULE" ]; then
-    # TODO: how to make CTRL-C work?
-    echo "WARNING: $SCHEDULE is null. Going to sleep."
-    tail -f /dev/null # do nothing forever
+  sh backup.sh
 else
   exec go-cron "$SCHEDULE" /bin/sh backup.sh
 fi