diff --git a/modules/backup.nix b/modules/backup.nix
index 2c0585ef..7ac2d3ca 100644
--- a/modules/backup.nix
+++ b/modules/backup.nix
@@ -5,7 +5,7 @@
     inherit (config.services.postgresql) enable;
     backupAll = true;
     compression = "zstd";
-    # compressionLevel = 9; # TODO: only available with 21.11
+    compressionLevel = 9;
     pgdumpOptions = "--create --clean";
     startAt = "*-*-* 06:00:00";
   };