diff --git a/defaults/main.yml b/defaults/main.yml
index 7e66df3..76a27dc 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -3,12 +3,15 @@ backups:
     retention:
       enabled: true
       OnCalendar: "1:{{ 60|random(seed=(inventory_hostname + 'backups_jobs')) }}"
+      lock_timeout: "{{ 6*60*60 }}"
     run:
       enabled: true
       OnCalendar: "3,11,19:{{ 60|random(seed=(inventory_hostname + 'backups_jobs')) }}"
+      lock_timeout: "{{ 6*60*60 }}"
     check:
       enabled: true
       OnCalendar: "monday 5:{{ 60|random(seed=(inventory_hostname + 'backups_jobs')) }}"
+      lock_timeout: "{{ 6*60*60 }}"
     export:
       enabled: false
       OnCalendar: "{{ [21,22,23]|random(seed=(inventory_hostname + 'backups_export_h')) }}:{{ 60|random(seed=(inventory_hostname + 'backups_export_m')) }}"
diff --git a/templates/backup-check.service.j2 b/templates/backup-check.service.j2
index 9f1dfb3..75fd992 100644
--- a/templates/backup-check.service.j2
+++ b/templates/backup-check.service.j2
@@ -6,5 +6,5 @@ OnFailure=status-email-root@%n.service
 Nice=19
 IOSchedulingClass=idle
 Type=simple
-ExecStart=/usr/local/bin/backup-check
+ExecStart=/bin/flock --timeout {{ backups.jobs.check.lock_timeout }} /run/backup-client.flock /usr/local/bin/backup-check
 
diff --git a/templates/backup-retention.service.j2 b/templates/backup-retention.service.j2
index 1900494..1be1496 100644
--- a/templates/backup-retention.service.j2
+++ b/templates/backup-retention.service.j2
@@ -6,5 +6,5 @@ OnFailure=status-email-root@%n.service
 Nice=19
 IOSchedulingClass=idle
 Type=simple
-ExecStart=/usr/local/bin/backup-retention
+ExecStart=/bin/flock --timeout {{ backups.jobs.retention.lock_timeout }} /run/backup-client.flock /usr/local/bin/backup-retention
 
diff --git a/templates/backup-run.service.j2 b/templates/backup-run.service.j2
index 9f277f4..aa78eb7 100644
--- a/templates/backup-run.service.j2
+++ b/templates/backup-run.service.j2
@@ -6,5 +6,5 @@ OnFailure=status-email-root@%n.service
 Nice=19
 IOSchedulingClass=idle
 Type=simple
-ExecStart=/usr/local/bin/backup-full
+ExecStart=/bin/flock --timeout {{ backups.jobs.run.lock_timeout }} /run/backup-client.flock /usr/local/bin/backup-full