diff --git a/prometheus/prometheus.sls b/prometheus/prometheus.sls
index ceb4e2c..ea9bbd3 100644
--- a/prometheus/prometheus.sls
+++ b/prometheus/prometheus.sls
@@ -14,6 +14,8 @@ prometheus:
   service:
     prometheus:
       args:
+        storage.tsdb.retention.time: 366d
+        storage.tsdb.retention: 366d
         web.listen-address: 0.0.0.0:9090
         log.level: warn
   config: