diff --git a/modules/module-list.nix b/modules/module-list.nix
index f3019d25..cb38af00 100644
--- a/modules/module-list.nix
+++ b/modules/module-list.nix
@@ -17,6 +17,7 @@
   ./system/defaults/alf.nix
   ./system/defaults/loginwindow.nix
   ./system/defaults/smb.nix
+  ./system/defaults/SoftwareUpdate.nix
   ./system/defaults/spaces.nix
   ./system/defaults/trackpad.nix
   ./system/etc.nix
diff --git a/modules/system/defaults-write.nix b/modules/system/defaults-write.nix
index adbe9394..6c79138d 100644
--- a/modules/system/defaults-write.nix
+++ b/modules/system/defaults-write.nix
@@ -29,6 +29,7 @@ let
   alf = defaultsToList "/Library/Preferences/com.apple.alf" cfg.alf;
   loginwindow = defaultsToList "/Library/Preferences/com.apple.loginwindow" cfg.loginwindow;
   smb = defaultsToList "/Library/Preferences/SystemConfiguration/com.apple.smb.server" cfg.smb;
+  SoftwareUpdate = defaultsToList "/Library/Preferences/SystemConfiguration/com.apple.SoftwareUpdate" cfg.SoftwareUpdate;
   screencapture = defaultsToList "com.apple.screencapture" cfg.screencapture;
   spaces = defaultsToList "com.apple.spaces" cfg.spaces;
   trackpad = defaultsToList "com.apple.AppleMultitouchTrackpad" cfg.trackpad;
@@ -40,13 +41,14 @@ in
 {
   config = {
 
-    system.activationScripts.defaults.text = mkIfAttrs [ alf loginwindow smb ]
+    system.activationScripts.defaults.text = mkIfAttrs [ alf loginwindow smb SoftwareUpdate ]
       ''
         # Set defaults
         echo >&2 "system defaults..."
         ${concatStringsSep "\n" alf}
         ${concatStringsSep "\n" loginwindow}
         ${concatStringsSep "\n" smb}
+        ${concatStringsSep "\n" SoftwareUpdate}
       '';
 
     system.activationScripts.userDefaults.text = mkIfAttrs
diff --git a/modules/system/defaults/SoftwareUpdate.nix b/modules/system/defaults/SoftwareUpdate.nix
new file mode 100644
index 00000000..ec89bce5
--- /dev/null
+++ b/modules/system/defaults/SoftwareUpdate.nix
@@ -0,0 +1,15 @@
+{ config, lib, ... }:
+
+with lib;
+
+{
+  options = {
+    system.defaults.SoftwareUpdate.AutomaticallyInstallMacOSUpdates = mkOption {
+      type = types.nullOr types.bool;
+      default = null;
+      description = ''
+        Automatically install Mac OS software updates. Defaults to false.
+      '';
+    };
+  };
+}