diff --git a/common/default.nix b/common/default.nix
index 25607bc..851858f 100644
--- a/common/default.nix
+++ b/common/default.nix
@@ -8,6 +8,7 @@
     ./direnv.nix
     ./fs.nix
     ./fwupd.nix
+    ./gc.nix
     ./git.nix
     ./nix.nix
     ./readline.nix
diff --git a/common/gc.nix b/common/gc.nix
new file mode 100644
index 0000000..5358d5a
--- /dev/null
+++ b/common/gc.nix
@@ -0,0 +1,7 @@
+{
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 30d";
+  };
+}