diff --git a/system/firefox.nix b/system/firefox.nix
index fdee3a1f..f8f82e2d 100644
--- a/system/firefox.nix
+++ b/system/firefox.nix
@@ -58,6 +58,11 @@
           installation_mode = "force_installed";
           install_url = "https://addons.mozilla.org/firefox/downloads/latest/catppuccin-mocha-lavender-git/latest.xpi";
         };
+        # Sweet-Dark theme
+        "{59f619c8-220b-4a27-8918-bf1537bc060a}" = {
+          installation_mode = "force_installed";
+          install_url = "https://addons.mozilla.org/firefox/downloads/latest/sweet-dark/latest.xpi";
+        };
       };
       FirefoxHome = {
         Search = true;