diff --git a/defaults/shell.nix b/defaults/shell.nix
index e76e8f7..e8df363 100644
--- a/defaults/shell.nix
+++ b/defaults/shell.nix
@@ -48,8 +48,8 @@ in
 
   config = lib.mkIf cfg.enable {
     # use Fish, the nicest shell :)
-    programs.fish.enable = true;
-    users.defaultUserShell = pkgs.fish;
+    programs.fish.enable = lib.mkIf config.nixowos.allowAddingPackages true;
+    users.defaultUserShell = lib.mkIf config.nixowos.allowAddingPackages pkgs.fish;
     # avoid generating caches (enabled by fish) due to slowdowns during nixos-rebuild
     # this may degrade autocompletion
     documentation.man.generateCaches = false;
@@ -64,11 +64,11 @@ in
     environment.systemPackages = lib.mkIf config.nixowos.allowAddingPackages cfg.extraPackages;
 
     # enter dev env on cd
-    programs.direnv = lib.mkDefault {
-      enable = true;
+    programs.direnv = {
+      enable = lib.mkIf config.nixowos.allowAddingPackages (lib.mkDefault true);
       # hide extra logging, that isn't particularly useful
       # (for only using nix at least)
-      settings.global.hide_env_diff = true;
+      settings.global.hide_env_diff = lib.mkDefault true;
     };
   };
 }