diff --git a/home/bat/default.nix b/home/bat/default.nix
index 1e810e8..94ddad6 100644
--- a/home/bat/default.nix
+++ b/home/bat/default.nix
@@ -19,11 +19,11 @@
     };
   };
 
-  programs.fish = lib.mkIf config.programs.fish.enable {
-    interactiveShellInit = ''
-      set -gx BATDIFF_USE_DELTA true
-    '';
+  home.sessionVariables = lib.mkIf config.home.preferXdgDirectories {
+    BATDIFF_USE_DELTA = true;
+  };
 
+  programs.fish = lib.mkIf config.programs.fish.enable {
     functions = {
       cat = {
         wraps = "bat";