diff --git a/nix/configurations/vanadium/home/firefox.nix b/nix/configurations/vanadium/home/firefox.nix
index aab6da3f..6edc85cb 100644
--- a/nix/configurations/vanadium/home/firefox.nix
+++ b/nix/configurations/vanadium/home/firefox.nix
@@ -8,7 +8,7 @@ let
 in
 {
   programs.firefox = {
-    enable = true;
+    enable = false;
 
     policies.SearchEngines.Add = [
       # Forges
diff --git a/nix/homeModules/common/zen-browser.nix b/nix/homeModules/common/zen-browser.nix
index c6681318..4b8227ea 100644
--- a/nix/homeModules/common/zen-browser.nix
+++ b/nix/homeModules/common/zen-browser.nix
@@ -52,12 +52,20 @@ in
     #
     # TODO: try out the "locked" semantic from zen
     # https://github.com/0xc000022070/zen-browser-flake/tree/main#preferences
+    #
+    # To check which option is mapped to which about:config
+    # - back preference file
+    #   cp .zen/default/prefs.js{,.bk}
+    # - click the buttons
+    # - diff it
+    #   diff .zen/default/prefs.js{.bk,}
     profiles.default = {
       settings = {
         "toolkit.legacyUserProfileCustomizations.stylesheets" = true;
         "browser.tabs.loadInBackground" = true;
         "browser.ctrlTab.sortByRecentlyUsed" = false;
         "layout.css.devPixelsPerPx" = 1.1;
+        "browser.startup.page" = 1;
 
         # open links in new window
         # this works a lot better with xmonad where I have a bunch of windows