diff --git a/roles/prometheus/tasks/main.yml b/roles/prometheus/tasks/main.yml
index faa2296..e3bbec8 100644
--- a/roles/prometheus/tasks/main.yml
+++ b/roles/prometheus/tasks/main.yml
@@ -21,6 +21,13 @@
   - Reload systemd
   - Restart prometheus-pve-exporter
 
+- name: Configure prometheus retention
+  lineinfile:
+    path: /etc/default/prometheus
+    regexp: '^ARGS=.*$'
+    line: 'ARGS="--storage.tsdb.retention.time=365d"'
+  notify: Restart prometheus
+
 - name: Configure prometheus
   template: src=prometheus.yml.j2 dest=/etc/prometheus/prometheus.yml
   notify: Restart prometheus