diff --git a/modules/crans/default.nix b/modules/crans/default.nix
index cac4a63..987aff5 100644
--- a/modules/crans/default.nix
+++ b/modules/crans/default.nix
@@ -17,6 +17,7 @@ in
     ./nullmailer.nix
     ./packages.nix
     ./ssh.nix
+    ./store.nix
     ./users.nix
     ./virtualisation.nix
   ];
diff --git a/modules/crans/store.nix b/modules/crans/store.nix
new file mode 100644
index 0000000..d57930c
--- /dev/null
+++ b/modules/crans/store.nix
@@ -0,0 +1,10 @@
+{...}:
+{
+  nix.gc = {
+    automatic = true;
+    dates = "04:15";
+    # avoid to run nix gc on all machine at the same time
+    randomizedDelaySec = "1h";
+    options = "--delete-older-than 14d";
+  };
+}