diff --git a/services/monitoring/prometheus.nix b/services/monitoring/prometheus.nix
index a7fee67..d040603 100644
--- a/services/monitoring/prometheus.nix
+++ b/services/monitoring/prometheus.nix
@@ -35,6 +35,8 @@
         ];
       }
     ];
+
+    retentionTime = "30d";
     globalConfig = {
       scrape_interval = "15s";
     };