diff --git a/Dockerfile b/Dockerfile
index 3aac76c..7a7bfd5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -39,10 +39,13 @@ ENV POSTGRES_DB="**None**" \
 COPY backup.sh /backup.sh
 RUN chmod +x backup.sh
 
+COPY init_script.sh /init_script.sh
+RUN chmod +x init_script.sh
+
 COPY hooks /hooks
 
 ENTRYPOINT ["/bin/sh", "-c"]
-CMD ["exec /usr/local/bin/go-cron -s \"$SCHEDULE\" -p \"$HEALTHCHECK_PORT\" -- /backup.sh"]
+CMD ["./init_script.sh"]
 
 HEALTHCHECK --interval=5m --timeout=3s \
   CMD curl -f "http://localhost:$HEALTHCHECK_PORT/" || exit 1
diff --git a/README.md b/README.md
index 9f23126..bb94455 100644
--- a/README.md
+++ b/README.md
@@ -70,20 +70,20 @@ docker run -d \
 |TELEGRAM_BOT_TOKEN         | Only used to call Telegram's public API             |
 
 ### Environmental variables
-| Name                   | Default value   | Description                               |
-|------------------------|  :------   |------------------------------------------------|
-| POSTGRES_DB            |  -         | Database name                                  |
-| POSTGRES_HOST          |  -         | PostgreSQL IP address or hostname              |
-| POSTGRES_PORT          | 5432       | Connection TCP port                            |
-| POSTGRES_USER          |  -         | Database user                                  |
-| POSTGRES_PASSWORD      |  -         | Database user password                         |
-| POSTGRES_EXTRA_OPTS    | --blobs    | Extra options `pg_dump` run                    |
-| SCHEDULE               | @daily     | `go-cron` schedule. See [this](#backup-using-go-cron) |
-| HEALTHCHECK_PORT       | 8080       | Port listening for cron-schedule health check. |
-| S3_ACCESS_KEY_ID       |  -         | Key or username with RW access to bucket       |
-| S3_SECRET_ACCESS_KEY   |  -         | Secret or password for `S3_ACCESS_KEY_ID`      |
-| S3_BUCKET              |  -         | Name of bucket created for backups             |
-| S3_ENDPOINT            |  -         | URL of S3 storage                              |
+| Name                   | Default value  | Is mandatory |  Description                               |
+|------------------------|  :------   |  :------:   |------------------------------------------------|
+| POSTGRES_DB            |  -         |   YES  | Database name                                  |
+| POSTGRES_HOST          |  -         |   YES  | PostgreSQL IP address or hostname              |
+| POSTGRES_PORT          | 5432       |   -  | Connection TCP port                            |
+| POSTGRES_USER          |  -         |   YES  | Database user                                  |
+| POSTGRES_PASSWORD      |  -         |   YES  | Database user password                         |
+| POSTGRES_EXTRA_OPTS    | --blobs    |   -  | Extra options `pg_dump` run                    |
+| SCHEDULE               | @daily     |   -  | `go-cron` schedule. See [this](#backup-using-go-cron) |
+| HEALTHCHECK_PORT       | 8080       |   -  | Port listening for cron-schedule health check. |
+| S3_ACCESS_KEY_ID       |  -         |   YES  | Key or username with RW access to bucket       |
+| S3_SECRET_ACCESS_KEY   |  -         |   YES  | Secret or password for `S3_ACCESS_KEY_ID`      |
+| S3_BUCKET              |  -         |   YES  | Name of bucket created for backups             |
+| S3_ENDPOINT            |  -         |   YES  | URL of S3 storage                              |
 
 ### Notification selection
 
diff --git a/backup.sh b/backup.sh
index 02897b9..3717add 100644
--- a/backup.sh
+++ b/backup.sh
@@ -3,7 +3,7 @@
 # Script made for backup PostgreSQL database from local (${POSTGRES_HOST}=127.0.0.1)
 # or remote host. Created backup stores in S3 storage. On completion script calls
 # notification scripts from hooks/ directory to send report to given Telegram Chat
-# based on variables set private or public notification method will be selected 
+# based on variables set private or public notification method will be selected
 
 set -euo pipefail
 IFS=$'\n\t'
diff --git a/init_script.sh b/init_script.sh
new file mode 100755
index 0000000..67311e9
--- /dev/null
+++ b/init_script.sh
@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+#
+# Script checks if mandatory variables are set and starts cron job for DB backup 
+
+set -euo pipefail
+IFS=$'\n\t'
+
+
+# Begin values check
+if [[ ${POSTGRES_DB} == "**None**" ]] ||
+   [[ ${S3_ACCESS_KEY_ID} == "**None**" ]] ||
+   [[ ${S3_SECRET_ACCESS_KEY} == "**None**" ]] ||
+   [[ ${S3_BUCKET} == "**None**" ]] ||
+   [[ ${S3_ENDPOINT} == "**None**" ]] ||
+   [[ ${POSTGRES_HOST} == "**None**" ]] ||
+   [[ ${POSTGRES_USER} == "**None**" ]] ||
+   [[ ${POSTGRES_PASSWORD} == "**None**" ]] ||
+   [[ ${S3_ACCESS_KEY_ID} == "**None**" ]]; then
+  echo "One or more mandatory values is missing. Check your configuration..." >&2
+  exit 0
+else
+# Will create base backup
+  echo "All needed variables seems set. Starting main procedure"
+  exec /usr/local/bin/go-cron -s $SCHEDULE -p $HEALTHCHECK_PORT -- /backup.sh
+fi