diff --git a/home/graphical/firefox/default.nix b/home/graphical/firefox/default.nix
index ebf726b..049a434 100644
--- a/home/graphical/firefox/default.nix
+++ b/home/graphical/firefox/default.nix
@@ -13,10 +13,15 @@ lib.mkIf osConfig.programs.firefox.enable {
       name = "ny";
       isDefault = true;
       userChrome = ''
-        /* hides the native tabs */
+        /* Hides the native tabs */
         #TabsToolbar {
             visibility: collapse;
         }
+        /* Fixed width for the sidebar */
+        #sidebar-box {
+            max-width: 17.5% !important;
+            min-width: 17.5% !important;
+        }
       '';
       settings = {
         "toolkit.legacyUserProfileCustomizations.stylesheets" = true;