diff --git a/nix/modules/home-manager/__programs/zen.nix b/nix/modules/home-manager/__programs/zen.nix
new file mode 100644
index 0000000..1e8415a
--- /dev/null
+++ b/nix/modules/home-manager/__programs/zen.nix
@@ -0,0 +1,51 @@
+{ config, lib, pkgs, home-manager, ... }:
+with lib;
+let
+  inherit (pkgs.stdenv.hostPlatform) isDarwin;
+
+  modulePath = [ "programs" "zen" ];
+  cfg = getAttrFromPath modulePath config;
+
+  mkFirefoxModule = import "${home-manager.outPath}/modules/programs/firefox/mkFirefoxModule.nix";
+
+  # Because Zen required ZenAvatarPath to be in profiles.ini
+  # REF: https://github.com/nix-community/home-manager/blob/60bb110917844d354f3c18e05450606a435d2d10/modules/programs/firefox/mkFirefoxModule.nix#L55-L69
+  profiles = flip mapAttrs' cfg.profiles (_: profile:
+    nameValuePair "Profile${toString profile.id}" {
+      Name = profile.name;
+      Path = if isDarwin then "Profiles/${profile.path}" else profile.path;
+      IsRelative = 1;
+      Default = if profile.isDefault then 1 else 0;
+      ZenAvatarPath = "chrome://browser/content/zen-avatars/avatar-1.svg";
+    }) // {
+      General = {
+        StartWithLastProfile = 1;
+      } // lib.optionalAttrs (cfg.profileVersion != null) {
+        Version = cfg.profileVersion;
+      };
+    };
+
+  profilesIni = generators.toINI { } profiles;
+in {
+  imports = [
+    (mkFirefoxModule {
+      inherit modulePath;
+      name = "Zen Browser";
+      wrappedPackageName = "zen";  # Imaginary wrappedPackageName so `programs.zen.policies` is added properly
+      visible = true;
+
+      platforms.linux = rec {
+        vendorPath = ".zen";
+        configPath = "${vendorPath}";
+      };
+      platforms.darwin = rec {
+        vendorPath = "Library/Application Support/Zen";
+        configPath = "${vendorPath}";
+      };
+    })
+  ];
+
+  config = {
+    home.file."${cfg.configPath}/profiles.ini" = mkForce (mkIf (cfg.profiles != { }) { text = profilesIni; });
+  };
+}
diff --git a/nix/modules/home-manager/zen.nix b/nix/modules/home-manager/zen.nix
new file mode 100644
index 0000000..7c0229e
--- /dev/null
+++ b/nix/modules/home-manager/zen.nix
@@ -0,0 +1,17 @@
+{ pkgs, config, vars, ... }:
+
+{
+  programs.zen = {
+    enable = true;
+    # REF: https://github.com/nix-community/home-manager/blob/342a1d682386d3a1d74f9555cb327f2f311dda6e/modules/programs/firefox/mkFirefoxModule.nix#L264
+    package = null;  # we only want the config
+    profiles.${config.home.username} = {
+      id = 0;
+      isDefault = true;
+    };
+
+    nativeMessagingHosts = [
+      pkgs.passff-host
+    ];
+  };
+}
diff --git a/nix/users/default.nix b/nix/users/default.nix
index e6e3284..8d84d3d 100644
--- a/nix/users/default.nix
+++ b/nix/users/default.nix
@@ -3,6 +3,10 @@
 let
   mkSystem = import ../lib/mkSystem.nix;
   mkBrew = import ../overlays/darwin/brew.nix;
+
+  defaultModules = [
+    ../modules/home-manager/__programs/zen.nix
+  ];
 in
 {
   # Host list
@@ -38,10 +42,11 @@ in
     home-manager.lib.homeManagerConfiguration {
       pkgs = pkgs-unstable;  # FIXME: switch to stable when 24.11 become stable
       extraSpecialArgs = { inherit inputs pkgs pkgs-unstable home-manager vars; };
-      modules = [
+      modules = defaultModules ++ [
         ./ziro
         ./ziro/darwin.nix
         ../modules/home-manager/floorp.nix
+        ../modules/home-manager/zen.nix
       ];
     };
 
@@ -59,10 +64,11 @@ in
     home-manager.lib.homeManagerConfiguration {
       pkgs = pkgs-unstable;  # FIXME: switch to stable when 24.11 become stable
       extraSpecialArgs = { inherit inputs pkgs pkgs-unstable home-manager vars; };
-      modules = [
+      modules = defaultModules ++ [
         ./ziro
         ./ziro/linux.nix
         ../modules/home-manager/floorp.nix
+        ../modules/home-manager/zen.nix
       ];
     };
 }
diff --git a/nix/users/ziro/default.nix b/nix/users/ziro/default.nix
index 37c72c0..05d522f 100644
--- a/nix/users/ziro/default.nix
+++ b/nix/users/ziro/default.nix
@@ -2,21 +2,23 @@
 
 let
   username = "ziro";
-  userChrome = builtins.replaceStrings ["/*ZI:*/18em/*:VERTICAL-TAB-HOVER-WIDTH-IN-EM*/"] ["${builtins.toString vars.floorp.verticalTabHoverWidthInEm}em"] (builtins.readFile ../../../include/floorp/ziro-userChrome.css);
-  settings = {
+  userChrome-ff-floorp = builtins.replaceStrings ["/*ZI:*/18em/*:VERTICAL-TAB-HOVER-WIDTH-IN-EM*/"] ["${builtins.toString vars.floorp.verticalTabHoverWidthInEm}em"] (builtins.readFile ../../../include/floorp/ziro-userChrome.css);
+  settings-ff-common = {
     "browser.toolbars.bookmarks.visibility" = "newtab";
-    "floorp.browser.sidebar.is.displayed" = false;
-    "floorp.browser.tabbar.settings" = 2;
-    "floorp.browser.tabs.verticaltab" = true;
-    "floorp.verticaltab.hover.enabled" = true;
-    "floorp.tabbar.style" = 2;
     "network.dns.disableIPv6" = true;
     "sidebar.position_start" = false;
     "signon.management.page.breach-alerts.enabled" = false;
     "signon.rememberSignons" = false;
     "extensions.autoDisableScopes" = 0;  # Auto enable extensions
   };
-  extensions = with pkgs.nur.repos.rycee.firefox-addons; [
+  settings-ff-floorp = settings-ff-common // {
+    "floorp.browser.sidebar.is.displayed" = false;
+    "floorp.browser.tabbar.settings" = 2;
+    "floorp.browser.tabs.verticaltab" = true;
+    "floorp.verticaltab.hover.enabled" = true;
+    "floorp.tabbar.style" = 2;
+  };
+  extensions-ff-common = with pkgs.nur.repos.rycee.firefox-addons; [
     # AdBlocker
     ublock-origin
 
@@ -40,11 +42,20 @@ in {
   };
 
   programs.floorp.profiles.${username} = {
-    inherit userChrome settings extensions;
+    userChrome = userChrome-ff-floorp;
+    settings = settings-ff-floorp;
+    extensions = extensions-ff-common;
   };
   programs.floorp.profiles.null = {
     id = 1;
-    inherit userChrome settings extensions;
+    userChrome = userChrome-ff-floorp;
+    settings = settings-ff-floorp;
+    extensions = extensions-ff-common;
+  };
+
+  programs.zen.profiles.${username} = {
+    settings = settings-ff-common;
+    extensions = extensions-ff-common;
   };
 
   xdg.configFile = {