diff --git a/modules/system/defaults/NSGlobalDomain.nix b/modules/system/defaults/NSGlobalDomain.nix
index 0f77d89..da8dd88 100644
--- a/modules/system/defaults/NSGlobalDomain.nix
+++ b/modules/system/defaults/NSGlobalDomain.nix
@@ -52,6 +52,19 @@ in {
       '';
     };
 
+    system.defaults.NSGlobalDomain.AppleIconAppearanceTheme = mkOption {
+      type = types.nullOr (types.enum [ "DarkRegular" "DarkAutomatic" "ClearLight" "Clear Dark" "Clear Automatic" "TintedLight" "TintedDark" "TintedAutomatic" ]);
+      default = null;
+      description = ''
+        Set icon and widget style
+
+        To set to default mode, set this to `null` and you'll need to manually run
+        {command}`defaults delete -g AppleIconAppearanceTheme`.
+
+        This option requires logging out and logging back in to apply.
+      '';
+    };
+
     system.defaults.NSGlobalDomain.AppleInterfaceStyleSwitchesAutomatically = mkOption {
       type = types.nullOr types.bool;
       default = null;
diff --git a/tests/fixtures/system-defaults-write/user.txt b/tests/fixtures/system-defaults-write/user.txt
index ca7334f..9041542 100644
--- a/tests/fixtures/system-defaults-write/user.txt
+++ b/tests/fixtures/system-defaults-write/user.txt
@@ -18,6 +18,11 @@ launchctl asuser "$(id -u -- test-defaults-user)" sudo --user=test-defaults-user
 <plist version="1.0">
 <true/>
 </plist>'
+launchctl asuser "$(id -u -- test-defaults-user)" sudo --user=test-defaults-user -- defaults write -g AppleIconAppearanceTheme '<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<string>DarkRegular</string>
+</plist>'
 launchctl asuser "$(id -u -- test-defaults-user)" sudo --user=test-defaults-user -- defaults write -g AppleKeyboardUIMode '<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
diff --git a/tests/system-defaults-write.nix b/tests/system-defaults-write.nix
index 6f67338..4af5512 100644
--- a/tests/system-defaults-write.nix
+++ b/tests/system-defaults-write.nix
@@ -26,6 +26,7 @@
   system.defaults.NSGlobalDomain.AppleEnableMouseSwipeNavigateWithScrolls = false;
   system.defaults.NSGlobalDomain.AppleEnableSwipeNavigateWithScrolls = false;
   system.defaults.NSGlobalDomain.AppleFontSmoothing = 1;
+  system.defaults.NSGlobalDomain.AppleIconAppearanceTheme = "DarkRegular";
   system.defaults.NSGlobalDomain.AppleICUForce24HourTime = true;
   system.defaults.NSGlobalDomain.AppleKeyboardUIMode = 3;
   system.defaults.NSGlobalDomain.ApplePressAndHoldEnabled = true;